NOAA TECHNICAL MEMORANDUM 

NWS WR-275 

 

 

 

CLIMATE OF SAN DIEGO, CALIFORNIA 

 

 

 

 

 

 

 

 

 

Third Edition 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Noel M. Isla, Jennifer L. Lee, 

National Weather Service Office 

San Diego, CA 

March 2006 

 

 

 

UNITED STATES 

DEPARTMENT OF COMMERCE 

Carlos Guiterrez, Secretary 

National Oceanic and Atmospheric Administration 

V. Adm.Conrad C. Lautenbacher Jr. (Ret.), 

Under Secretary of Commerce for Oceans 

and Atmosphere and NOAA Administrator 

National Weather Service 

Brig. Gen. David L. Johnson (Ret.), 

Assistant Administrator for Weather Services 

 

 
ii

 

 

NOAA TECHNICAL MEMORANDA 

National Weather Service, Western 

Region Subseries

The National Weather Service (NWS) Western 

Region (WR) Subseries provides an informal medium 

for the documentation and quick dissemination of 

results not appropriate, or not yet ready, for formal 

publication. The series is used to report on work in progress, to describe 

technical procedures and practices, or to relate progress to a limited audience. 

These Technical Memoranda will report on investigations devoted primarily to 

regional and local problems of interest mainly to personnel, and hence will not 

be widely distributed. 

Papers 1 to 25 are in the former series, ESSA Technical Memoranda, Western 

Region Technical Memoranda (WRTM); papers 24 to 59 are in the former 

series, ESSA Technical Memoranda, Weather Bureau Technical Memoranda 

(WBTM). Beginning with 60, the papers are part of the series, NOAA Technical 

Memoranda NWS. Out-of-print memoranda are not listed. 

Papers 2 to 22, except for 5 (revised edition), are available from the National 

Weather Service Western Region, Scientific Services Division, 125 South State 

Street - Rm 1311, Salt Lake City, Utah 84138-1102. Paper 5 (revised edition), 

and all others beginning with 25 are available from the National Technical 

Information Service, U.S. Department of Commerce, Sills Building, 5285 Port 

Royal Road, Springfield, Virginia 22161. Prices vary for all paper copies; 

microfiche are $3.50. Order by accession number shown in parentheses at end 

of each entry. 

 ESSA Technical Memoranda (WRTM)

 2 Climatological Precipitation Probabilities. Compiled by Lucianne Miller, 

December 1965. 

 3 Western Region Pre- and Post-FP-3 Program, December 1, 1965, to 

February 20, 1966. Edward D. Diemer, March 1966. 

 5 Station Descriptions of Local Effects on Synoptic Weather Patterns. Philip 

Williams, Jr., April 1966 (Revised November 1967, October 1969). (PB17800) 

 8 Interpreting the RAREP. Herbert P. Benner, May 1966 (Revised January 

1967). 

11 Some Electrical Processes in the Atmosphere. J. Latham, June 1966. 

17 A Digitalized Summary of Radar Echoes within 100 Miles of Sacramento, 

California. J. A. Youngberg and L. B. Overaas, December 1966. 

21 An Objective Aid for Forecasting the End of East Winds in the Columbia 

Gorge, July through October. D. John Coparanis, April 1967. 

22 Derivation of Radar Horizons in Mountainous Terrain. Roger G. Pappas, 

April 1967. 

ESSA Technical Memoranda, Weather Bureau Technical Memoranda 

(WBTM) 

25 Verification of Operation Probability of Precipitation Forecasts, April 1966-

March 1967. W. W. Dickey, October 1967. (PB-176240) 

26 A Study of Winds in the Lake Mead Recreation Area. R. P. Augulis, 

January 1968. (PB-177830) 

28 Weather Extremes. R. J. Schmidli, April 1968 (Revised March 1986). 

(PB86 177672/AS). (Revised October 1991 - PB92-115062/AS) 

29 Small-Scale Analysis and Prediction. Philip Williams, Jr., May 1968. 

(PB178425) 

30 Numerical Weather Prediction and Synoptic Meteorology. CPT Thomas D. 

Murphy, USAF, May 1968. (AD 673365) 

31 Precipitation Detection Probabilities by Salt Lake ARTC Radars. Robert K. 

Belesky, July 1968. (PB 179084) 

32 Probability Forecasting--A Problem Analysis with Reference to the Portland 

Fire Weather District. Harold S. Ayer, July 1968. (PB 179289) 

36 Temperature Trends in Sacramento--Another Heat Island. Anthony D. 

Lentini, February 1969. (PB 183055) 

37 Disposal of Logging Residues Without Damage to Air Quality. Owen P. 

Cramer, March 1969. (PB 183057) 

39 Upper-Air Lows Over Northwestern United States. A.L. Jacobson, April 

1969. PB 184296) 

40 The Man-Machine Mix in Applied Weather Forecasting in the 1970s. L.W. 

Snellman, August 1969. (PB 185068) 

43 Forecasting Maximum Temperatures at Helena, Montana. David E. Olsen, 

October 1969. (PB 185762) 

44 Estimated Return Periods for Short-Duration Precipitation in Arizona. Paul 

C. Kangieser, October 1969. (PB 187763) 

46 Applications of the Net Radiometer to Short-Range Fog and Stratus 

Forecasting at Eugene, Oregon. L. Yee and E. Bates, December 1969. 

(PB 190476) 

47 Statistical Analysis as a Flood Routing Tool. Robert J.C. Burnash, 

December 1969. (PB 188744) 

48 Tsunami. Richard P. Augulis, February 1970. (PB 190157) 

49 Predicting Precipitation Type. Robert J.C. Burnash and Floyd E. Hug, 

March 1970. (PB 190962) 

50 Statistical Report on Aeroallergens (Pollens and Molds) Fort Huachuca, 

Arizona, 1969. Wayne S. Johnson, April 1970. (PB 191743) 

51 Western Region Sea State and Surf Forecaster's Manual. Gordon C. 

Shields and Gerald B. Burdwell, July 1970. (PB 193102) 

52 Sacramento Weather Radar Climatology. R.G. Pappas and C. M. 

Veliquette, July 1970. (PB 193347) 

54 A Refinement of the Vorticity Field to Delineate Areas of Significant 

Precipitation. Barry B. Aronovitch, August 1970. 

55 Application of the SSARR Model to a Basin without Discharge Record. 

Vail Schermerhorn and Donal W. Kuehl, August 1970. (PB 194394) 

56 Areal Coverage of Precipitation in Northwestern Utah. Philip Williams, Jr., 

and Werner J. Heck, September 1970. (PB 194389) 

57 Preliminary Report on Agricultural Field Burning vs. Atmospheric Visibility 

in the Willamette Valley of Oregon. Earl M. Bates and David O. Chilcote, 

September 1970. (PB 194710) 

58 Air Pollution by Jet Aircraft at Seattle-Tacoma Airport. Wallace R. 

Donaldson, October 1970. (COM 71 00017) 

59 Application of PE Model Forecast Parameters to Local-Area Forecasting. 

Leonard W. Snellman, October 1970. (COM 71 00016) 

60 An Aid for Forecasting the Minimum Temperature at Medford, Oregon, 

Arthur W. Fritz, October 1970. (COM 71 00120) 

63 700-mb Warm Air Advection as a Forecasting Tool for Montana and 

Northern Idaho. Norris E. Woerner, February 1971. (COM 71 00349) 

64 Wind and Weather Regimes at Great Falls, Montana. Warren B. Price, 

March 1971. 

65 Climate of Sacramento, California. Laura Masters-Bevan. NWSO 

Sacramento, November 1998 (6th Revision. (PB99-118424) 

66 A Preliminary Report on Correlation of ARTCC Radar Echoes and 

Precipitation. Wilbur K. Hall, June 1971. (COM 71 00829) 

69 National Weather Service Support to Soaring Activities. Ellis Burton, 

August 1971. (COM 71 00956) 

71 Western Region Synoptic Analysis-Problems and Methods. Philip 

Williams, Jr., February 1972. (COM 72 10433) 

74 Thunderstorms and Hail Days Probabilities in Nevada. Clarence M. 

Sakamoto, April 1972. (COM 72 10554) 

75 A Study of the Low Level Jet Stream of the San Joaquin Valley. Ronald A. 

Willis and Philip Williams, Jr., May 1972. (COM 72 10707) 

76 Monthly Climatological Charts of the Behavior of Fog and Low Stratus at 

Los Angeles International Airport. Donald M. Gales, July 1972. (COM 72 

11140) 

77 A Study of Radar Echo Distribution in Arizona During July and August. 

John E. Hales, Jr., July 1972. (COM 72 11136) 

78 Forecasting Precipitation at Bakersfield, California, Using Pressure 

Gradient Vectors. Earl T. Riddiough, July 1972. (COM 72 11146) 

79 Climate of Stockton, California. Robert C. Nelson, July 1972. (COM 72 

10920) 

80 Estimation of Number of Days Above or Below Selected Temperatures. 

Clarence M. Sakamoto, October 1972. (COM 72 10021) 

81 An Aid for Forecasting Summer Maximum Temperatures at Seattle, 

Washington. Edgar G. Johnson, November 1972. (COM 73 10150) 

82 Flash Flood Forecasting and Warning Program in the Western Region. 

Philip Williams, Jr., Chester L. Glenn, and Roland L. Raetz, December 

1972, (Revised March 1978). (COM 73 10251) 

83 A comparison of Manual and Semiautomatic Methods of Digitizing Analog 

Wind Records. Glenn E. Rasch, March 1973. (COM 73 10669) 

86 Conditional Probabilities for Sequences of Wet Days at Phoenix, Arizona. 

Paul C. Kangieser, June 1973. (COM 73 11264) 

87 A Refinement of the Use of K-Values in Forecasting Thunderstorms in 

Washington and Oregon. Robert Y.G. Lee, June 1973. (COM 73 11276) 

89 Objective Forecast Precipitation Over the Western Region of the United 

States. Julia N. Paegle and Larry P. Kierulff, September 1973. (COM 73 

11946/3AS) 

91 Arizona "Eddy" Tornadoes. Robert S. Ingram, October 1973. (COM 73 

10465) 

92 Smoke Management in the Willamette Valley. Earl M. Bates, May 1974. 

(COM 74 11277/AS) 

93 An Operational Evaluation of 500-mb Type Regression Equations. 

Alexander E. MacDonald, June 1974. (COM 74 11407/AS) 

94 Conditional Probability of Visibility Less than One-Half Mile in Radiation 

Fog at Fresno, California. John D. Thomas, August 1974. (COM 74 

11555/AS) 

95 Climate of Flagstaff, Arizona. Paul W. Sorenson, and updated by Reginald 

W. Preston, January 1987. (PB87 143160/AS) 

96 Map type Precipitation Probabilities for the Western Region. Glenn E. 

Rasch and Alexander E. MacDonald, February 1975. (COM 75 

10428/AS) 

97 Eastern Pacific Cut-Off Low of April 21-28, 1974. William J. Alder and 

George R. Miller, January 1976. (PB 250 711/AS) 

98 Study on a Significant Precipitation Episode in Western United States. Ira 

S. Brenner, April 1976. (COM 75 10719/AS) 

99 A Study of Flash Flood Susceptibility-A Basin in Southern Arizona. Gerald 

Williams, August 1975. (COM 75 11360/AS) 

102 A Set of Rules for Forecasting Temperatures in Napa and Sonoma 

Counties. Wesley L. Tuft, October 1975. (PB 246 902/AS) 

103 Application of the National Weather Service Flash-Flood Program in the 

Western Region. Gerald Williams, January 1976. (PB 253 053/AS) 

104 Objective Aids for Forecasting Minimum Temperatures at Reno, Nevada, 

During the Summer Months. Christopher D. Hill, January 1976. (PB 252 

866/AS) 

105 Forecasting the Mono Wind. Charles P. Ruscha, Jr., February 1976. (PB 

254 650) 

106 Use of MOS Forecast Parameters in Temperature Forecasting. John C. 

Plankinton, Jr., March 1976. (PB 254 649) 

107 Map Types as Aids in Using MOS PoPs in Western United States. Ira S. 

Brenner, August 1976. (PB 259 594) 

108 Other Kinds of Wind Shear. Christopher D. Hill, August 1976. (PB 260 

437/AS) 

109 Forecasting North Winds in the Upper Sacramento Valley and Adjoining 

Forests. Christopher E. Fontana, September 1976. (PB 273 677/AS) 

110 Cool Inflow as a Weakening Influence on Eastern Pacific Tropical 

Cyclones. William J. Denney, November 1976. (PB 264 655/AS) 

112 The MAN/MOS Program. Alexander E. MacDonald, February 1977. (PB 
iii

265 941/AS) 

113 Winter Season Minimum Temperature Formula for Bakersfield, California, 

Using Multiple Regression. Michael J. Oard, February 1977. (PB 273 

694/AS) 

114 Tropical Cyclone Kathleen. James R. Fors, February 1977. (PB 273 

676/AS) 

116 A Study of Wind Gusts on Lake Mead. Bradley Colman, April 1977. (PB 

268 847) 

117 The Relative Frequency of Cumulonimbus Clouds at the Nevada Test Site 

as a Function of K-Value. R.F. Quiring, April 1977. (PB 272 831) 

118 Moisture Distribution Modification by Upward Vertical Motion. Ira S. 

Brenner, April 1977. (PB 268 740) 

119 Relative Frequency of Occurrence of Warm Season Echo Activity as a 

Function of Stability Indices Computed from the Yucca Flat, Nevada, 

Rawinsonde. Darryl Randerson, June 1977. (PB 271 290/AS) 

121 Climatological Prediction of Cumulonimbus Clouds in the Vicinity of the 

Yucca Flat Weather Station. R.F. Quiring, June 1977. (PB 271 704/AS) 

122 A Method for Transforming Temperature Distribution to Normality. Morris 

S. Webb, Jr., June 1977. (PB 271 742/AS) 

124 Statistical Guidance for Prediction of Eastern North Pacific Tropical 

Cyclone Motion - Part I. Charles J. Neumann and Preston W. Leftwich, 

August 1977. (PB 272 661) 

125 Statistical Guidance on the Prediction of Eastern North Pacific Tropical 

Cyclone Motion - Part II. Preston W. Leftwich and Charles J. Neumann, 

August 1977. (PB 273 155/AS) 

126 Climate of San Francisco. E. Jan Null, February 1978. (Revised by 

George T. Pericht, April 1988 and January 1995). (PB88 208624/AS) 

127 Development of a Probability Equation for Winter-Type Precipitation 

Patterns in Great Falls, Montana. Kenneth B. Mielke, February 1978. 

(PB 281 387/AS) 

128 Hand Calculator Program to Compute Parcel Thermal Dynamics. Dan 

Gudgel, April 1978. (PB 283 080/AS) 

129 Fire whirls. David W. Goens, May 1978. (PB 283 866/AS) 

130 Flash-Flood Procedure. Ralph C. Hatch and Gerald Williams, May 1978. 

(PB 286 014/AS) 

131 Automated Fire-Weather Forecasts. Mark A. Mollner and David E. Olsen, 

September 1978. (PB 289 916/AS) 

132 Estimates of the Effects of Terrain Blocking on the Los Angeles WSR-74C 

Weather Radar. R.G. Pappas, R.Y. Lee, B.W. Finke, October 1978. (PB 

289767/AS) 

133 Spectral Techniques in Ocean Wave Forecasting. John A. Jannuzzi, 

October 1978. (PB291317/AS) 

134 Solar Radiation. John A. Jannuzzi, November 1978. (PB291195/AS) 

135 Application of a Spectrum Analyzer in Forecasting Ocean Swell in 

Southern California Coastal Waters. Lawrence P. Kierulff, January 1979. 

 (PB292716/AS) 

136 Basic Hydrologic Principles. Thomas L. Dietrich, January 1979. 

(PB292247/AS) 

137 LFM 24-Hour Prediction of Eastern Pacific Cyclones Refined by Satellite 

Images. John R. Zimmerman and Charles P. Ruscha, Jr., January 1979. 

 (PB294324/AS) 

138 A Simple Analysis/Diagnosis System for Real Time Evaluation of Vertical 

Motion. Scott Heflick and James R. Fors, February 1979. 

(PB294216/AS) 

139 Aids for Forecasting Minimum Temperature in the Wenatchee Frost 

District. Robert S. Robinson, April 1979. (PB298339/AS) 

140 Influence of Cloudiness on Summertime Temperatures in the Eastern 

Washington Fire Weather district. James Holcomb, April 1979. 

(PB298674/AS) 

141 Comparison of LFM and MFM Precipitation Guidance for Nevada During 

Doreen. Christopher Hill, April 1979. (PB298613/AS) 

142 The Usefulness of Data from Mountaintop Fire Lookout Stations in 

Determining Atmospheric Stability. Jonathan W. Corey, April 1979. 

(PB298899/AS) 

143 The Depth of the Marine Layer at San Diego as Related to Subsequent 

Cool Season Precipitation Episodes in Arizona. Ira S. Brenner, May 

1979. (PB298817/AS) 

144 Arizona Cool Season Climatological Surface Wind and Pressure Gradient 

Study. Ira S. Brenner, May 1979. (PB298900/AS) 

146 The BART Experiment. Morris S. Webb, October 1979. (PB80 155112) 

147 Occurrence and Distribution of Flash Floods in the Western Region. 

Thomas L. Dietrich, December 1979. (PB80 160344) 

149 Misinterpretations of Precipitation Probability Forecasts. Allan H. Murphy, 

Sarah Lichtenstein, Baruch Fischhoff, and Robert L. Winkler, February 

1980. (PB80 174576) 

150 Annual Data and Verification Tabulation - Eastern and Central North 

Pacific Tropical Storms and Hurricanes 1979. Emil B. Gunther and Staff, 

EPHC, April 1980. (PB80 220486) 

151 NMC Model Performance in the Northeast Pacific. James E. Overland, 

PMEL-ERL, April 1980. (PB80 196033) 

152 Climate of Salt Lake City, Utah. William J. Alder, Sean T. Buchanan, 

William Cope (Retired), James A. Cisco, Craig C. Schmidt, Alexander R. 

Smith (Retired), Wilbur E. Figgins (Retired), February 1998 - Seventh 

Revision (PB98-130727) 

153 An Automatic Lightning Detection System in Northern California. James E. 

Rea and Chris E. Fontana, June 1980. (PB80 225592) 

154 Regression Equation for the Peak Wind Gust 6 to 12 Hours in Advance at 

Great Falls During Strong Downslope Wind Storms. Michael J. Oard, July 

1980. (PB91 108367) 

155 A Raininess Index for the Arizona Monsoon. John H. Ten Harkel, July 

1980. (PB81 106494) 

156 The Effects of Terrain Distribution on Summer Thunderstorm Activity at 

Reno, Nevada. Christopher Dean Hill, July 1980. (PB81 102501) 

157 An Operational Evaluation of the Scofield/Oliver Technique for Estimating 

Precipitation Rates from Satellite Imagery. Richard Ochoa, August 1980. 

(PB81 108227) 

158 Hydrology Practicum. Thomas Dietrich, September 1980. (PB81 134033) 

159 Tropical Cyclone Effects on California. Arnold Court, October 1980. 

(PB81 133779) 

160 Eastern North Pacific Tropical Cyclone Occurrences During Intraseasonal 

Periods. Preston W. Leftwich and Gail M. Brown, February 1981. (PB81 

205494) 

161 Solar Radiation as a Sole Source of Energy for Photovoltaics in Las 

Vegas, Nevada, for July and December. Darryl Randerson, April 1981. 

(PB81 224503) 

162 A Systems Approach to Real-Time Runoff Analysis with a Deterministic 

Rainfall-Runoff Model. Robert J.C. Burnash and R. Larry Ferral, April 

1981. (PB81 224495) 

163 A Comparison of Two Methods for Forecasting Thunderstorms at Luke Air 

Force Base, Arizona. LTC Keith R. Cooley, April 1981. (PB81 225393) 

164 An Objective Aid for Forecasting Afternoon Relative Humidity Along the 

Washington Cascade East Slopes. Robert S. Robinson, April 1981. 

(PB81 23078) 

165 Annual Data and Verification Tabulation, Eastern North Pacific Tropical 

Storms and Hurricanes 1980. Emil B. Gunther and Staff, May 1981. 

(PB82 230336) 

166 Preliminary Estimates of Wind Power Potential at the Nevada Test Site. 

Howard G. Booth, June 1981. (PB82 127036) 

167 ARAP User's Guide. Mark Mathewson, July 1981, Revised September 

1981. (PB82 196783) 

168 Forecasting the Onset of Coastal Gales Off Washington-Oregon. John R. 

Zimmerman and William D. Burton, August 1981. (PB82 127051) 

169 A Statistical-Dynamical Model for Prediction of Tropical Cyclone Motion in 

the Eastern North Pacific Ocean. Preston W. Leftwich, Jr., October 1981. 

(PB82195298) 

170 An Enhanced Plotter for Surface Airways Observations. Andrew J. Spry 

and Jeffrey L. Anderson, October 1981. (PB82 153883) 

171 Verification of 72-Hour 500-MB Map-Type Predictions. R.F. Quiring, 

November 1981. (PB82-158098) 

172 Forecasting Heavy Snow at Wenatchee, Washington. James W. 

Holcomb, December 1981. (PB82-177783) 

173 Central San Joaquin Valley Type Maps. Thomas R. Crossan, December 

1981. (PB82 196064) 

174 ARAP Test Results. Mark A. Mathewson, December 1981. (PB82 

198103) 

176 Approximations to the Peak Surface Wind Gusts from Desert 

Thunderstorms. Darryl Randerson, June 1982. (PB82 253089) 

177 Climate of Phoenix, Arizona. Robert J. Schmidli and Austin Jamison, April 

1969 (Revised July 1996). (PB96-191614) 

178 Annual Data and Verification Tabulation, Eastern North Pacific Tropical 

Storms and Hurricanes 1982. E.B. Gunther, June 1983. (PB85 106078) 

179 Stratified Maximum Temperature Relationships Between Sixteen Zone 

Stations in Arizona and Respective Key Stations. Ira S. Brenner, June 

1983. (PB83 249904) 

180 Standard Hydrologic Exchange Format (SHEF) Version I. Phillip A. 

Pasteris, Vernon C. Bissel, David G. Bennett, August 1983. (PB85 

106052) 

181 Quantitative and Spacial Distribution of Winter Precipitation along Utah's 

Wasatch Front. Lawrence B. Dunn, August 1983. (PB85 106912) 

182 500 Millibar Sign Frequency Teleconnection Charts - Winter. Lawrence B. 

Dunn, December 1983. (PB85 106276) 

183 500 Millibar Sign Frequency Teleconnection Charts - Spring. Lawrence B. 

Dunn, January 1984. (PB85 111367) 

184 Collection and Use of Lightning Strike Data in the Western U.S. During 

Summer 1983. Glenn Rasch and Mark Mathewson, February 1984. 

(PB85 110534) 

185 500 Millibar Sign Frequency Teleconnection Charts - Summer. Lawrence 

B. Dunn, March 1984. (PB85 111359) 

186 Annual Data and Verification Tabulation eastern North Pacific Tropical 

Storms and Hurricanes 1983. E.B. Gunther, March 1984. (PB85 109635) 

187 500 Millibar Sign Frequency Teleconnection Charts - Fall. Lawrence B. 

Dunn, May 1984. (PB85-110930) 

188 The Use and Interpretation of Isentropic Analyses. Jeffrey L. Anderson, 

October 1984. (PB85-132694) 

189 Annual Data & Verification Tabulation Eastern North Pacific Tropical 

Storms and Hurricanes 1984. E.B. Gunther and R.L. Cross, April 1985. 

(PB85 1878887AS) 

190 Great Salt Lake Effect Snowfall: Some Notes and An Example. David M. 

Carpenter, October 1985. (PB86 119153/AS) 

191 Large Scale Patterns Associated with Major Freeze Episodes in the 

Agricultural Southwest. Ronald S. Hamilton and Glenn R. Lussky, 

December 1985. (PB86 144474AS) 

192 NWR Voice Synthesis Project: Phase I. Glen W. Sampson, January 

1986. (PB86 145604/AS) 

193 The MCC - An Overview and Case Study on Its Impact in the Western 

United States. Glenn R. Lussky, March 1986. (PB86 170651/AS) 

194 Annual Data and Verification Tabulation Eastern North Pacific Tropical 

Storms and Hurricanes 1985. E.B. Gunther and R.L. Cross, March 1986. 

(PB86 170941/AS) 

195 Radid Interpretation Guidelines. Roger G. Pappas, March 1986. (PB86 

177680/AS) 

196 A Mesoscale Convective Complex Type Storm over the Desert Southwest. 

 Darryl Randerson, April 1986. (PB86 190998/AS) 

197 The Effects of Eastern North Pacific Tropical Cyclones on the 

Southwestern United States. Walter Smith, August 1986. (PB87 

106258AS) 

198 Preliminary Lightning Climatology Studies for Idaho. Christopher D. Hill, 

Carl J. Gorski, and Michael C. Conger, April 1987. (PB87 180196/AS) 

199 Heavy Rains and Flooding in Montana: A Case for Slantwise Convection. 

Glenn R. Lussky, April 1987. (PB87 185229/AS) 

200 Annual Data and Verification Tabulation Eastern North Pacific Tropical 

Storms and Hurricanes 1986. Roger L. Cross and Kenneth B. Mielke, 

September 1987. (PB88 110895/AS) 
iv

201 An Inexpensive Solution for the Mass Distribution of Satellite Images. 

Glen W. Sampson and George Clark, September 1987. (PB88 

114038/AS) 

202 Annual Data and Verification Tabulation Eastern North Pacific Tropical 

Storms and Hurricanes 1987. Roger L. Cross and Kenneth B. Mielke, 

September 1988. (PB88-101935/AS) 

203 An Investigation of the 24 September 1986 "Cold Sector" Tornado 

Outbreak in Northern California. John P. Monteverdi and Scott A. Braun, 

October 1988. (PB89 121297/AS) 

204 Preliminary Analysis of Cloud-To-Ground Lightning in the Vicinity of the 

Nevada Test Site. Carven Scott, November 1988. (PB89 128649/AS) 

205 Forecast Guidelines For Fire Weather and Forecasters -- How Nighttime 

Humidity Affects Wildland Fuels. David W. Goens, February 1989. (PB89 

162549/AS) 

206 A Collection of Papers Related to Heavy Precipitation Forecasting. 

Western Region Headquarters, Scientific Services Division, August 1989. 

 (PB89 230833/AS) 

207 The Las Vegas McCarran International Airport Microburst of August 8, 

1989. Carven A. Scott, June 1990. (PB90-240268) 

208 Meteorological Factors Contributing to the Canyon Creek Fire Blowup, 

September 6 and 7, 1988. David W. Goens, June 1990. (PB90-245085) 

209 Stratus Surge Prediction Along the Central California Coast. Peter Felsch 

and Woodrow Whitlatch, December 1990. (PB91-129239) 

210 Hydrotools. Tom Egger. January 1991. (PB91-151787/AS) 

211 A Northern Utah Soaker. Mark E. Struthwolf, February 1991. (PB91-

168716) 

212 Preliminary Analysis of the San Francisco Rainfall Record: 1849-1990. 

Jan Null, May 1991. (PB91-208439) 

213 Idaho Zone Preformat, Temperature Guidance, and Verification. Mark A. 

Mollner, July 1991. (PB91-227405/AS) 

214 Emergency Operational Meteorological Considerations During an 

Accidental Release of Hazardous Chemicals. Peter Mueller and Jerry 

Galt, August 1991. (PB91-235424) 

215 WeatherTools. Tom Egger, October 1991. (PB93-184950) 

216 Creating MOS Equations for RAWS Stations Using Digital Model Data. 

Dennis D. Gettman, December 1991. (PB92-131473/AS) 

217 Forecasting Heavy Snow Events in Missoula, Montana. Mike Richmond, 

May 1992. (PB92-196104) 

218 NWS Winter Weather Workshop in Portland, Oregon. Various Authors, 

December 1992. (PB93-146785) 

219 A Case Study of the Operational Usefulness of the Sharp Workstation in 

Forecasting a Mesocyclone-Induced Cold Sector Tornado Event in 

California. John P. Monteverdi, March 1993. (PB93-178697) 

220 Climate of Pendleton, Oregon. Claudia Bell, August 1993. (PB93-227536) 

221 Utilization of the Bulk Richardson Number, Helicity and Sounding 

Modification in the Assessment of the Severe Convective Storms of 3 

August 1992. Eric C. Evenson, September 1993. (PB94-131943) 

222 Convective and Rotational Parameters Associated with Three Tornado 

Episodes in Northern and Central California. John P. Monteverdi and 

John Quadros, September 1993. (PB94-131943) 

223 Climate of San Luis Obispo, California. Gary Ryan, February 1994. 

(PB94-162062) 

224 Climate of Wenatchee, Washington. Michael W. McFarland, Roger G. 

Buckman, and Gregory E. Matzen, March 1994. (PB94-164308) 

225 Climate of Santa Barbara, California. Gary Ryan, December 1994. (PB95-

173720) 

226 Climate of Yakima, Washington. Greg DeVoir, David Hogan, and Jay 

Neher, December 1994. (PB95-173688) 

227 Climate of Kalispell, Montana. Chris Maier, December 1994. (PB95-

169488) 

228 Forecasting Minimum Temperatures in the Santa Maria Agricultural 

District. Wilfred Pi and Peter Felsch, December 1994. (PB95-171088) 

229 The 10 February 1994 Oroville Tornado--A Case Study. Mike 

Staudenmaier, Jr., April 1995. (PB95-241873) 

230 Santa Ana Winds and the Fire Outbreak of Fall 1993. Ivory Small, June 

1995. (PB95-241865) 

231 Washington State Tornadoes. Tresté Huse, July 1995. (PB96-107024) 

232 Fog Climatology at Spokane, Washington. Paul Frisbie, July 1995. 

(PB96-106604) 

233 Storm Relative Isentropic Motion Associated with Cold Fronts in Northern 

Utah. Kevin B. Baker, Kathleen A. Hadley, and Lawrence B. Dunn, July 

1995. (PB96-106596) 

234 Some Climatological and Synoptic Aspects of Severe Weather 

Development in the Northwestern United States. Eric C. Evenson and 

Robert H. Johns, October 1995. (PB96-112958) 

235 Climate of Las Vegas, Nevada. Paul H. Skrbac and Scott Cordero, 

December 1995. (PB96-135553) 

236 Climate of Astoria, Oregon. Mark A. McInerney, January 1996. 

237 The 6 July 1995 Severe Weather Events in the Northwestern United 

States: Recent Examples of SSWEs. Eric C. Evenson, April 1996. 

238 Significant Weather Patterns Affecting West Central Montana. Joe Lester, 

May 1996. (PB96-178751) 

239 Climate of Portland, Oregon. Clinton C. D. Rockey, May 1996. (PB96-

17603) - First Revision, October 1999 

240 Downslop Winds of Santa Barbara, CA. Gary Ryan, July 1996. (PB96-

191697) 

241 Operational Applications of the Real-time National Lightning Detection 

Network Data at the NWSO Tucson, AZ. Darren McCollum, David Bright, 

Jim Meyer, and John Glueck, September 1996. (PB97-108450) 

242 Climate of Pocatello, Idaho. Joe Heim, October 1996. (PB97-114540) 

243 Climate of Great Falls. Montana. Matt Jackson and D. C. Williamson, 

December 1996. (PB97-126684) 

244 WSR-88D VAD Wind Profile Data Influenced by Bird Migration over the 

Southwest United States. Jesus A. Haro, January 1997. (PB97-135263) 

245 Climatology of Cape for Eastern Montana and Northern Wyoming. Heath 

Hockenberry and Keith Meier, January 1997. (PB97-133425) 

246 A Western Region Guide to the Eta-29 Model. Mike Staudenmaier, Jr., 

March 1997. (PB97-144075) 

247 The Northeast Nevada Climate Book. Edwin C. Clark, March 1997. (First 

Revision - January 1998 - Andrew S. Gorelow and Edwin C. Clark - 

PB98-123250) 

248 Climate of Eugene, Oregon. Clinton C. D. Rockey, April 1997. (PB97-

155303) 

249 Climate of Tucson, Arizona. John R. Glueck, October 1997 

250 Northwest Oregon Daily Extremes and Normans. Clinton C. D. Rockey, 

October 1997 

251 A Composite Study Examining Five Heavy Snowfall Patterns for SouthCentral Montana. Jonathan D. Van Ausdall and Thomas W. Humphrey. 

February 1998. (PB98-125255) 

252 Climate of Eureka, California. Alan H. Puffer. February 1998. (PB98-

130735) 

253 Inferenced Oceanic Kelvin/Rossby Wave Influence on North American 

West Coast Precipitation. Martin E. Lee and Dudley Chelton. April 1998. 

 (PB98-139744) 

254 Conditional Symmetric InstabilityCMethods of Operational Diagnosis and 

Case Study of 23-24 February 1994 Eastern Washington/Oregon 

Snowstorm. Gregory A. DeVoir. May 1998. (PB98-144660) 

255 Creation and Maintenance of a Comprehensive Climate Data Base. 

Eugene Petrescu. August 1998. (PB98-173529) 

256 Climate of San Diego, California. Thomas E. Evans, III and Donald A. 

Halvorson. October 1998. (PB99-109381) 

257 Climate of Seattle, Washington. Dana Felton. November 1998. (PB99-

113482) 

258 1985-1998 North Pacific Tropical Cyclones Impacting the Southwestern 

United States and Northern Mexico: An Updated Climatology. Armando 

L. Garza. January 1999. (PB99-130502) 

259 Climate of San Jose, California. Miguel Miller. April 1999. (PB99-145633) 

260 Climate of Las Vegas, Nevada. Paul H. Skrbac. December 1999 

261 Climate of Los Angeles, California. David Bruno, Gary Ryan, with 

assistance from Curt Kaplan and Jonathan Slemmer. January 2000 

262 Climate of Miles City, Montana. David A. Spector and Mark H. Strobin. 

April 2000 

263 Analysis of Radiosonde Data for Spokane, Washington. Rocco D. Pelatti. 

 November 2000 

264 Climate of Billings, Montana. Jeffrey J. Zeltwanger and Mark H. Strobin. 

November 2000 

265 Climate of Sheridan, Wyoming. Jeffrey J. Zeltwanger, Sally Springer, Mark 

H. Strobin. March 2001 

266 Climate of Sacramento, California. Laura Masters-Bevan. December 

2000 (7th Revision) 

267 Sulphur Mountain Doppler Radar: A Performance Study. Los 

Angeles/Oxnard WFO. August 2001 

268 Prediction of Heavy Snow Events in the Snake River Plain Using Pattern 

Recognition and Regression Techniques. Thomas Andretta and William 

Wojcik, October 2003. 

269 The Lewis and Clark Expedition 1803-1806, Weather, Water and Climate. 

Vernon Preston. December 2004 

270. Climate of San Diego California. Emmanuel M. Isla, Steve Vanderburg, 

Christopher Medjber, Daniel Paschall, December 2004. 

271 Climate of Las Vegas, Nevada. Revised by Andrew S. Gorelow, January 

2005. Previous Edition Paul H. Skrbac. December 1999 

272 Climate of Sacramento, California. Laura A. Bevan, George Cline, Revised 

June 2005. 

273 Climate of Flagstaff, AZ. 4th Edition by Michael Staudenmier Jr. Reginald 

Preston (R) Paul Sorenson (R) August 2005. 

274 Climate of Prescott, AZ by Bob Fogarty, Michael Staudenmier Jr. 

Flagstaff, AZ, August 2005 

275 Climate of San Diego, CA, 3rd Edition by Noel M. Isla, Jennifer L. Lee, 

March 2006 
This publication has been reviewed 

and is approved for publication by 

Scientific Services Division, 

Western Region 

Delain A. Edman, Chief 

Scientific Services Division 

Salt Lake City, Utah 

 

iii
TABLE OF CONTENTS

 PAGE

I. Introduction ........ ............. ............................ ............. ............. .............. ............. ............. ......... 1 

II. The City of San Diego...... ............................ ............. ............. .............. ............. ............. ......... 2 

III. History.. ............. ............. ............................ ............. ............. .............. ............. ............. ......... 3 

IV. Temperatures...... ............. ............................ ............. ............. .............. ............. ............. ......... 4 

V. Precipitation ....... ............. ............................ ............. ............. .............. ............. ............. ......... 8 

VI. Wind..... ............. ............. ............................ ............. ............. .............. ............. ............. ......... 12 

VII. Pressure ............. ............. ............................ ............. ............. .............. ............. ............. ......... 13 

VIII. Relative Humidity ............ ............................ ............. ............. .............. ............. ............. ......... 13 

IX. Air Quality ......... ............. ............................ ............. ............. .............. ............. ............. ......... 14 

X. Sky Cover, Clouds, Fog and Haze................. ............. ............. .............. ............. ............. ......... 15 

XI. Coastal Eddy ...... ............. ............................ ............. ............. .............. ............. ............. ......... 15 

XII. Our Changing Climate ..... ............................ ............. ............. .............. ............. ............. ......... 16 

XIII. Acknowledgments............ ............................ ............. ............. .............. ............. ............. ......... 18 

XIV. References .......... ............. ............................ ............. ............. .............. ............. ............. ......... 18 

iv
LIST OF FIGURES, CHARTS AND TABLES

LIST OF FIGURES PAGE

1. Map of San Diego County ............................ ............. ............. .............. ............. ............. ......... 20 

2. Weather Station Locations of San Diego ...... ............. ............. .............. ............. ............. ........ 21 

LIST OF CHARTS

1. Climograph ........ ............. ............................ ............. ............. .............. ............. ............. ......... 27 

2. Mean Annual, Mean Annual Maximum, Mean Annual Minimum Temperature... ............. ......... 28 

3. Normal Station Pressure... ............................ ............. ............. .............. ............. ............ ......... 50 

4. Total Seasonal Precipitation.......................... ............. ............. .............. ............. ............. ......... 54 

5. Thunderstorm Days .......... ............................ ............. ............. .............. ............. ............. ......... 86 

6. Annual Fog and Dense Fog Days.................. ............. ............. .............. ............. ............. ......... 92 

7. Annual Haze Days............ ............................ ............. ............. .............. ............. ............. ......... 95 

8. Annual Surfline Water Temperature ............. ............. ............. .............. ............. ............. ......... 97 

9. Peak Annnual Wind ......... ............................ ............. ............. .............. ............. ............. ........ 102 

10. Air Quality Violation Days ........................... ............. ............. .............. ............. ............. ........ 104 

LIST OF TABLES 

1. Miscellaneous Means and Extremes ............. ............. ............. .............. ............. ............. ......... 22 

2. Daily Normals of Temperature, Heating and Cooling Days and 

 Precipitation ....... ............. ............................ ............. ............. .............. ............. ............. ......... 23 

3. Mean Monthly Temperatures ........................ ............. ............. .............. ............. ............. ......... 29 

4. Temperature Readings of 100 Degrees and Higher..... ............. .............. ............. ............. ......... 34 

V 

PAGE 
5. Temperature Readings of 32 Degrees and Cooler....... ............. .............. ............. ............. ......... 35 

6. Mean Yearly Temperatures in Descending Order....... ............. .............. ............. ............. ......... 36 

7. Highest and Lowest Daily Temperatures ...... ............. ............. .............. ............. ............. ......... 37 

8. Pressure Statistics............. ............................ ............. ............. .............. ............. ............. ......... 49 

9. Monthly and Seasonal Precipitation.............. ............. ............. .............. ............. ............. ......... 55 

10. Greatest Daily Precipitation .......................... ............. ............. .............. ............. ............. ......... 61 

11. Number of Consecutive Days with No Measurable Precipitation............ ............. ............. ......... 64 

12. Years that Measurable Precipitation Fell Every Month ............ .............. ............. ............. ......... 64 

13. Maximum Monthly Precipitation with Four Inches or More .... .............. ............. ............. ......... 65 

14. Greatest Rainfall for a Calendar Day ............ ............. ............. .............. ............. ............. ......... 66 

15. Precipitation Statistics by the Month............. ............. ............. .............. ............. ............. ......... 67 

16. Return Period - Maximum Precipitation ....... ............. ............. .............. ............. ............. ......... 69 

17. Significant Maximum and Minimum Monthly Rainfall............ .............. ............. ............. ......... 70 

18. Days with Thunderstorms ............................ ............. ............. .............. ............. ............. ......... 82 

19. Number of Days with Fog Reported ............. ............. ............. .............. ............. ............. ......... 87 

20. Number of Days with Dense Fog Reported... ............. ............. .............. ............. ............. ......... 90 

21. Number of Days with Haze Reported ........... ............. ............. .............. ............. ............. ......... 93 

22. Average Daily Surfline Water Temperature for Mission Beach .............. ............. ............. ......... 96 

23. Mean Monthly Wind Direction for Each Hour of the Day........ .............. ............. ............. ......... 98 

24. Mean Monthly Wind Speed for Each Hour of the Day in Knots ............. ............. ............. ......... 99 

24. Peak Wind Gust for Each Month of Each Year in Miles Per Hour .......... ............. ............. ........ 100 

25. Number of Days Not Satisfying the Air Quality Standards in Parts of 

 Ozone Per Hundred Million Parts of Air....... ............. ............. .............. ............. ............. ........ 103 

vi
THE CLIMATE OF SAN DIEGO, CALIFORNIA 

Third Edition 

March 2006 

Noel M. Isla and Jennifer L. Lee 

First Edition by 

Thomas E. Evans, III 

Donald A. Halvorson 

I. INTRODUCTION

The city of San Diego, California has a 

Mediterranean climate with some surprising 

and unique features. The National Weather 

Service (NWS) has never issued a 

climatology of San Diego, but in 1913, the 

San Diego Chamber of Commerce, in 

cooperation with the NWS (at the time 

known as the United States Weather 

Bureau), published a book entitled “The 

Climate and Weather of San Diego, 

California.” The climatological stations 

used in the 1913 study, and again in this 

paper, were based on the official weather 

stations in the downtown area. Many 

agencies had responsibility for taking and 

recording observations for San Diego. 

These agencies included the NWS (United 

States Weather Bureau), Medical Corps of 

the Army and the Army Signal Corps 

(Signal Service). There have been many 

changes in the location and monitoring 

practices of the observations, but each one 

was, and still is, considered official. 

Today, several departments maintain 

weather observing equipment both in and 

outside of the city. These agencies include 

the NWS, Federal Aviation Administration, 

United States Forest Service (U.S. Forest 

Service), State of California Department of 

Water Resources, San Diego Flood Control 

District, City of San Diego Water Utilities 

Department, U.S. Geological Survey, 

Caltrans, International Boundary 

Commission, San Diego Air Pollution 

Control District and the Department of 

Defense. 

This paper represents an effort to assemble 

the latest relevant climatological data for the 

city of San Diego. Within this paper, longterm temperature records are analyzed, 

precipitation trends are fully discussed and 

research into many other significant weather 

factors which affect the city are outlined, 

including hurricanes, Santa Ana winds, and 

thunderstorms. In addition, many tables are 

included to help understand the climate of 

San Diego. The result is designed to be an 

overview of the local climate of the 

downtown area, including Lindbergh Field, 

for the city of San Diego. Included in some 

sections are proverbs and folklore. 

The city of San Diego has a fairly long- term 

official weather record dating back to the 

middle of the 19th century, but it has been 

said that San Diego has the shortest 

thermometer in the United States. This may 

be true, but the weather is not always as 

serene as this statement makes one believe: 

 
2

What is it moulds the life of man? 

 The weather. 

 What makes some black and others tan? 

 The weather. 

 What makes the Zulu live in trees? 

 And Congo natives dress in leaves? 

 While others go in furs and freeze? 

 The weather. 

II. THE CITY OF SAN DIEGO

On the edge of the San Diego Bay, in the 

southwest corner of California, lies the city 

of San Diego. It is this proximity to the 

water that is the dominating factor in San 

Diego’s climate: prevailing winds and 

weather are moderated by the Pacific Ocean. 

This results in cool summers and warm 

winters in comparison with other places 

along the same general latitude. 

Temperatures of freezing or below have 

rarely occurred at the station since the 

record began in 1871, but temperatures 

greater than 90 degrees are more frequent. 

Dry easterlies, often termed “Santa Ana” 

winds, sometimes blow in Southern 

California for several days at a time, 

allowing San Diego temperatures to reach 

into the 90s and occasionally above 100 

degrees, especially in the eastern sections of 

the city and the outlying areas. As these hot 

winds are predominant in the fall, most of 

the highest temperatures occur in the months 

of September and October. June is the only 

other month in which the 100 degree mark 

has been surpassed. These high 

temperatures are accompanied by very low 

relative humidity, which often drop below 

20 percent and occasionally below 10 

percent. 

A marked feature of the climate is the wide 

variation in temperature within short 

distances. Just outside of San Diego proper, 

the days are much warmer in the summer 

and the nights are noticeably cooler in the 

winter. Also, freezing occurs much more 

frequently than in the city. Although 

records show small daily temperature ranges 

in the city, only about 15 degrees between 

the highest and lowest readings, a few miles 

inland these ranges increase to 30 degrees or 

more. 

Strong winds and gales associated with 

Pacific or tropical storms are infrequent due 

to the latitude (32° North). The 

predominant winds during the day are from 

the west-northwest, with light southeasterly 

winds generally occurring at night. 

Occasionally, south to southwest winds will 

develop during the day due to a coastal eddy 

formation. When an eddy is present the low 

clouds that normally dissipate in the 

morning become widespread and can remain 

over the area throughout the day. 

The seasonal rainfall is about 10 inches in 

the city, but varies with elevation and 

distance from the coast. In the mountains to 

the north and east the average is between 20 

and 40 inches, depending on slope and 

elevation. Most of the precipitation falls in 

winter, with occasional summer mountain 

thunderstorms. There is a large range of 

monthly and seasonal precipitation totals, 

but approximately 85 percent of the rainfall 

occurs from November through March. At 

the official downtown San Diego station, 

hail is infrequent and snow is very rare. 

As on the rest of the Pacific Coast, a 

dominant characteristic of spring and 

summer is the night and early morning 

cloudiness. Low clouds form regularly, and 

frequently extend inland over the coastal 

valleys and foothills, but they usually 

dissipate during the morning leaving the 

afternoons clear. 
3

Considerable fog occurs along the coast, 

with the fall and winter months usually the 

foggiest. As a general rule, however, 

visibilities are good, with an average year 

only recording 23 days of dense fog (defined 

as visibility of 1⁄4 mile or less). Sunshine is 

plentiful for a marine location, with a 

marked increase as one travels towards the 

interior. As for thunderstorms, they are rare, 

averaging about three a year in the city. 

III. HISTORY

As Captain Juan Rodriguez Cabrillo entered 

San Diego Bay in September, 1542, he 

recorded in his log: 

 A very great gale blew from the southwest; the 

 port being good, we felt nothing.

This is the first record of a meteorological 

observation in San Diego’s history. Official 

United States Government records of 

weather, however, have only been available 

in San Diego since July 1, 1849. At that 

time, the observations were taken and 

recorded under the supervision of the 

Medical Corps of the Army at the San Diego 

Mission de Alcala, which was located on 

Presidio Hill in Presidio Park. It was the 

responsibility of the Post Surgeon to record 

the temperature and overall weather 

conditions. While under the care of the 

Medical Corps, the observing location was 

moved twice. In 1850, the new site became 

Old Fort Stockton, south of the mission, but 

still in Presidio Park. In 1860, the second 

move was onto the new U.S. Military Post at 

the H Street (now Market Street) barracks. 

This agreement continued until instruments 

and records were transferred to the Signal 

Service in 1871. 

On November 1, 1871, the U.S. Congress 

assigned responsibility for forecasting 

storms on lakes and seacoasts to the War 

Department. The Army Signal Corps 

(Signal Service) was given these new duties. 

Once the Army Signal Corps took control of 

weather services in San Diego, observations 

were again moved and taken in Horton 

Square on D Street (now Broadway) 

between 3rd and 4th Avenues. Through the 

next 6 decades, until January, 1930, the 

observing site changed several more times, 

but remained in the downtown area. Each of 

the downtown sites was located within a 

1000 foot radius of the present day Horton 

Plaza. 

By 1890, the Weather Bureau was founded 

and its office/observing site was located on 

5th Avenue between E and F Streets. The 

Weather Bureau moved to its final 

downtown location on April 1, 1914, where 

observations continued through January, 

1940. On January 15, 1930, another 

Weather Bureau Office was established at 

the Lindbergh Municipal Airport, 1.5 miles 

northwest of the downtown office. 

Observations were recorded, but did not 

become official until February 1, 1940. 

The final move of the observation 

equipment was made on August 13, 1969, to 

the Port of San Diego General Aviation 

Building at Lindbergh Field, San Diego’s 

International Airport. The Lindbergh Field 

observing site was augmented in 1996 by 

Automated Surface Observation System 

(ASOS), enabling easier data access. 

IV. TEMPERATURES

The temperatures in San Diego are highly 

dependent on the direction of the low level 

flow and the associated airmass upwind. 

For example, an onshore southwest wind 

will increase the marine layer depth, thus 

mild temperatures will result. For the most 

part, the surface wind has a westerly 
4

component. This allows the marine layer to 

develop in the evenings and dissipate in the 

mornings. The morning low cloud burn-off 

time determines the amount of heating the 

surface receives and, therefore, greatly 

influences afternoon temperatures. 

Likewise, the time the marine layer develops 

at night will determine the rate of cooling 

and affect the morning low temperature. 

Therefore, the strength of the onshore low 

level flow will help determine maximum 

and minimum temperatures. 

When an offshore low level flow develops, 

the winds may become easterly and inhibit 

marine layer formation. This is when the 

area can receive its hottest days (mainly in 

the summer) and its coldest nights (mainly 

in the winter). 

The average annual temperature in the 

downtown area, based on 1971 to 2000 data, 

is 64.4 degrees. The average daily 

maximum and minimum temperatures are 

70.8 and 58.1 degrees, respectively. 

Average daily maximum temperatures peak 

in late August and early September at 78 

degrees, and drop to 65 degrees in late 

December and early January. The average 

daily minimum temperatures peak at 68 

degrees in August and drop to 48 degrees in 

mid-late December. 

Although moderate temperatures are the 

expected due to the marine influence, 

temperature extremes do occur. The highest 

temperature ever recorded occurred during a 

Santa Ana wind event on September 26, 

1963. The lowest temperature took place on 

the morning of January 7, 1913, during a 

cold offshore wind event. These events are 

detailed in the following sections. 

 If the barometer and the thermometer 

 Both rise together, 

 It is a very sure sign 

 Of coming fine weather. 

Temperature Extremes

In San Diego, the temperature extremes 

almost always occur during offshore flow. 

During the summer and early fall the 

airmass to the east of San Diego has the 

potential of becoming quite hot, while 

during the winter and early spring the 

eastern airmass has the potential of 

becoming quite cold. Both of these air 

masses are generally dry and associated with 

surface high pressure. 

Hot weather, however, is not always 

associated with offshore flow. Sometimes, 

high temperatures occur with light winds 

while strong high pressure resides overhead. 

In this situation, temperatures can reach 85 

to 95 degrees in the summer. San Diego has 

only been at or above 100 degrees 24 times 

between 1872 and 2005. The highest 

temperature recorded downtown was 111 

degrees, on September 26, 1963. 

As with the high temperatures, lower 

temperatures are not always associated with 

offshore flow. Sometimes cool conditions 

occur when the synoptic pattern advects cold 

northern air into the San Diego area. 

Generally, this cold air originates over 

Canada. San Diego has only been at or 

below freezing 11 times. The lowest 

temperature was 25 degrees, recorded on 

January 7, 1913. 

Cold is the night, 

 When the stars shine bright. 

The Hottest Day in History

THURSDAY, SEPTEMBER 26, 1963: 

A SCORCHING HEAT WAVE SPREAD OVER ALL OF 

SOUTHERN CALIFORNIA AS SEVERE SANTA ANA 
5

CONDITIONS DEVELOPED WITH EXTREMELY 

HIGH TEMPERATURES, LOW HUMIDITIES, AND 

STRONG, GUSTY, EASTERLY WINDS. 

A MASSIVE HIGH PRESSURE AREA OVER NEVADA 

AND UTAH PUSHED WINDS UP TO 50 MILES PER 

HOUR (MPH) THROUGH THE MOUNTAINS. 

TREES WERE DOWNED AND FLYING DEBRIS 

BROKE OR SHORTED MANY POWER LINES. 

WINDS WERE UP TO 30 MPH IN MANY PARTS OF 

THE CITY. LINDBERGH FIELD HAD A 

PREVAILING WIND FOR THE DAY FROM THE 

EAST-NORTHEAST AND THE AVERAGE SPEED 

WAS 6.9 MILES PER HOUR. THE STRONGEST 

GUST WAS 18 MPH FROM THE EAST. 

SAN DIEGO SIZZLED AS THE TEMPERATURE 

SOARED TO A RECORD HIGH OF 111 DEGREES,

SURPASSING THE PREVIOUS RECORD OF 110

DEGREES SET 50 YEARS EARLIER ON SEPTEMBER 

17, 1913. THIS WAS A NEW HIGH FOR THE DAY,

FOR THE MONTH, AND FOR THE YEAR. THIS WAS 

THE WORST HEAT WAVE IN HISTORY, DUE NOT 

ONLY TO THE EXTREMELY HIGH TEMPERATURES 

BUT ALSO THE DURATION OF THOSE EXTREMES. 

IT WAS UNUSUAL IN THAT IT STARTED OUT 

WARM, WITH A LOW OF 73 DEGREES AFTER THE 

PREVIOUS DAY’S HIGH OF 96 DEGREES,

WARMED UP VERY QUICKLY, AND REMAINED 

HOT. THIS REMAINS THE ONLY DAY THE 

TEMPERATURE WAS 95 DEGREES AT 8 IN THE 

MORNING. THERE WERE 11 HOURS OF 90

DEGREES AND HIGHER, 7 HOURS OVER 100

DEGREES, AND 6 HOURS OF 105 DEGREES AND 

WARMER, WITH A TEMPERATURE OF 111

DEGREES HOLDING FOR MORE THAN ONE HOUR. 

RELATIVE HUMIDITY WAS AS LOW AS 6 PERCENT 

AT LINDBERGH FIELD AND 12 PERCENT AT EL 

CAJON. 

EXCEPT FOR THE MOUNTAINS, TEMPERATURES 

OVER THE ENTIRE COUNTY WERE IN TRIPLE 

DIGITS. SKYLINE LODGE ON PALOMAR 

MOUNTAIN REPORTED 78 DEGREES AND 

WARNER SPRINGS 91 DEGREES. WITH 

EASTERLY WINDS, THE COASTAL AREAS WERE 

WARM: CARLSBAD AND OCEANSIDE BOTH 

REPORTED 108 DEGREES, IMPERIAL BEACH 

109 DEGREES, BUT CORONADO REACHED 96

DEGREES. THOUSANDS OF BEACH GOERS 

PEERING OUT AT THE OCEAN AT MISSION 

BEACH HAD WINDS AT THEIR BACKS AND A 

TEMPERATURE OF 100 DEGREES JUST A FEW 

FEET FROM THE SURF. SAN DIEGO STATE 

UNIVERSITY REPORTED 107 DEGREES ALONG 

WITH LEMON GROVE, LA MESA, AND 

ESCONDIDO. GILLESPIE FIELD REPORTED 108

DEGREES ALONG WITH CHULA VISTA, BUT THE 

CITY OF EL CAJON REACHED 112 DEGREES. 

NATIONAL CITY, VISTA, AND FALLBROOK ALL 

HAD READINGS OF 106 DEGREES. 

UNOFFICIAL REPORTS HAD BOTH LA JOLLA AND 

PACIFIC BEACH AT 113 DEGREES, LOGAN 

HEIGHTS AT 122 DEGREES, 118 DEGREES IN 

NORTH PARK AND 115 DEGREES AT MIRAMAR.

THE MARINE CORPS AIR STATION AT EL TORO 

WAS OFFICIALLY THE HOTTEST SPOT IN THE 

UNITED STATES WITH 113 DEGREES, AND SAN 

DIEGO WAS SECOND WITH 111 DEGREES. 

THIS HEAT WAVE WAS THE WORST IN HISTORY. 

IT DAMAGED CROPS AND KILLED 30,000

CHICKENS AND 200,000 RABBITS. THREE 

PEOPLE WERE TREATED FOR HEAT 

PROSTRATION. ICE CREAM AND SOFT DRINK 

SALES SOARED. AIR CONDITIONED THEATERS 

AND MOTELS FILLED RAPIDLY. CARS WERE 

STALLED BY VAPOR LOCK AND BOILING 

RADIATORS. COMPUTERS WERE TURNED OFF 

AT THE NAVAL SUPPLY CENTER WHEN THEY 

BECAME TOO HOT. THE CITY AUTHORIZED ALL 

FEMALE EMPLOYEES TO LEAVE EARLY BECAUSE 

OF ADVERSE WORKING CONDITIONS. 

POLICEMEN LEFT THEIR TIES OFF AND ROLLED 

UP THEIR SLEEVES. 

STIFLING HEAT TURNED MANY CITY AND 

COUNTY CLASSROOMS INTO OVENS ON THE 
6

26TH, AND SEVERAL SCHOOL DISTRICTS,

INCLUDING SAN DIEGO, DECLARED 

ABBREVIATED SESSIONS FOR THE 27TH. CITY 

JUNIOR COLLEGES REMAINED ON THEIR 

REGULAR SCHEDULE. IT WAS THE FIRST TIME 

SINCE SEPTEMBER, 1939 THAT CITY SCHOOLS 

HAVE BEEN DISMISSED BECAUSE OF HIGH 

TEMPERATURES. 

BACK COUNTRY FIRE DANGER INCREASED 

BECAUSE OF EXTREME DRYNESS AND GUSTY 

WINDS BUT NO SERIOUS FIRES WERE REPORTED. 

DESPITE THE HEAT IN SOUTHERN CALIFORNIA,

AND ESPECIALLY SAN DIEGO, THE OFFICIAL 

CITY TEMPERATURE WAS NOT QUITE AS HIGH AS 

THAT AT 4TH AVENUE AND B STREET. THE 

TEMPERATURE SIGN THERE FLASHED 134

DEGREES.

The Coldest Day in History

TUESDAY, JANUARY 7, 1913: 

PROPHETS AND SEERS, FOR EITHER OCCULT 

REASONS OR SUPERSTITIONS, HAD FILLED THE 

PUBLIC WITH PROMISES OF CALAMITIES IN A 

YEAR, ENDING IN 13, DEVOID OF LUCK. 

WITH SOME MORNING LOW CLOUDS,

NORTHEAST WINDS, A LOW OF 48 DEGREES AND 

HIGH OF 61 DEGREES, JANUARY 1, 1913, WAS A 

NEAR NORMAL DAY. THEN, IT STARTED TO 

WARM UP AS NORTH TO NORTHEAST WINDS AND 

100 PERCENT SUNSHINE CONTINUED. A HIGH 

OF 73 DEGREES ON THE 2ND WAS FOLLOWED BY 

78 DEGREES ON THE 3RD, WHICH WAS 16

DEGREES ABOVE NORMAL. WINDS BECAME 

EASTERLY ON THE 4TH AND THE MAXIMUM 

TEMPERATURE WAS 20 DEGREES LOWER THAN 

THE DAY BEFORE. IT CONTINUED TO GET 

COLDER WITH STRONGER NORTHEAST WINDS 

AND SKIES REMAINING MOSTLY CLEAR. A LOW 

OF 36 DEGREES AND A HIGH OF ONLY 47

DEGREES WERE RECORDED ON THE 5TH. THE 

MINIMUM TEMPERATURE ON THE MORNING OF 

THE 6TH WAS 28.4 DEGREES UNDER CLEAR 

SKIES AND A 5 KNOT NORTHEAST WIND. THE 

THERMOMETER CLIMBED VERY SLOWLY AND 

ONLY REACHED 45 DEGREES BY NOON, THE 

LOWEST MAXIMUM EVER RECORDED, AND SKIES 

WERE STILL CLEAR. 

SAN DIEGANS WERE BEGINNING TO BUNDLE UP 

AND GATHER AT THE WEATHER KIOSK IN THE 

PLAZA TO WATCH THE THERMOMETERS. WITH 

FROSTED BREATH THEY PRESSED THEIR NOSES 

AGAINST THE PROTECTIVE GLASS TO SEE THE 

CURRENT TEMPERATURE. NATIVES WERE 

BEWILDERED, AS THEY HAD NEVER 

EXPERIENCED COLD WEATHER LIKE THIS. 

TEMPERATURES AT THE KIOSK WERE ABOUT 6

DEGREES LOWER THAN AT THE WEATHER 

BUREAU AT 5TH AND F, SO THE HIGH 

TEMPERATURE IN THE PLAZA COULD HAVE 

BEEN AS LOW AS 40 DEGREES. 

TEMPERATURES BEGAN TO DROP THAT 

AFTERNOON, BUT PEOPLE STILL REMAINED IN 

THE PLAZA. THE TEMPERATURE DROPPED TO 

32 DEGREES AT 9 PM AND 29DEGREES AT 

MIDNIGHT. PEOPLE WERE STILL HUDDLING 

AGAINST THE COLD AND OCCASIONALLY STRUCK 

MATCHES TO SEE HOW LOW THE TEMPERATURE 

WAS. AT 1 AM IT WAS DOWN TO 24 DEGREES,

AND THE LAST READING AT 2 AM WAS 22

DEGREES. THE WEATHER BUREAU LOW,

WHICH WAS RECORDED AT 6 AM, WAS 24.9

DEGREES. AT MIDNIGHT, THE KIOSK 

TEMPERATURE WAS 4 DEGREES LOWER THAN 

THE WEATHER BUREAU’S, SO THE PLAZA 

MINIMUM WOULD HAVE BEEN LOWER THAN 

24.9 DEGRESS, AND POSSIBLY AS LOW AS 21

DEGREES. SKIES WERE CLEAR WITH LIGHT 

NORTHEAST WINDS AS THE SUN ROSE ON THE 

COLDEST MORNING IN SAN DIEGO HISTORY. 

OTHER LOW TEMPERATURES THAT BITTERLY 

COLD MORNING WERE: CAMPO 4 DEGREES,

CUYAMACA 9 DEGREES, ALPINE 13 DEGREES,
7

JULIAN AND LAKESIDE 15 DEGREES, EL CAJON 

20 DEGREES, LEMON GROVE 22 DEGREES, LA 

MESA 24 DEGREES, AND CHULA VISTA 26

DEGREES. THERE WAS A KILLING FREEZE ALL 

OVER THE COUNTY. 

FRUIT GROWERS WERE UNPREPARED AND NO 

ARRANGEMENTS HAD BEEN MADE. SOME 

HASTILY ATTEMPTED TO BUILD SMUDGE FIRES,

BUT SOON LEARNED THERE WAS NO FUEL ON 

HAND TO BURN, WHILE OTHERS PASSED THE 

NIGHT PICKING AS MUCH AS POSSIBLE. 

IT WAS NOT MUCH BETTER IN OTHER PARTS OF 

SOUTHERN CALIFORNIA, AS SMUDGE POTS BY 

THE THOUSANDS WERE FIRED UP IN A FIGHT TO 

SAVE A CITRUS CROP VALUED AT $50,000,000. 

DENSE CLOUDS OF BLACK PUNGENT SMOKE 

FROM THE BURNING OF CRUDE OIL HOVERED 

OVER ORANGE AND LEMON LADEN TREES. 

BLAZING DISTILLATE BURNERS DOTTED 

HILLSIDES AND VALLEYS, ILLUMINATING SMOKE 

CLOUDS OVERHEAD. 

SOME WATER PIPES FROZE AND A FEW BURST. 

SUBURBAN TROLLEY LINES WERE DISRUPTED BY 

FREEZING OF AIR BRAKE LINES. FLOWERS WERE 

DESTROYED. FISHERMEN WERE PREVENTED 

FROM MAKING THIS DAILY TRIP TO SEA BECAUSE 

THEIR NETS WERE FROZEN TO THEIR REELS.

MANY YOUNGSTERS WENT TO THE PLAZA 

FOUNTAIN TO SEE ICE FOR THE FIRST TIME, AND 

CLIMBED OVER THE RIM AND STOOD ON THE 3/4

INCH THICK ICE. ONE BOY FROM THE 

NORTHERN PART OF THE COUNTRY, WHO 

BROUGHT ICE SKATES WITH HIM, SKATED IN THE 

FOUNTAIN AND WAS THE ENVY OF THE LOCAL 

BOYS. HE WAS OFFERED A POCKET KNIFE, AND 

EVEN UP TO 10 CENTS IN ACTUAL MONEY, BUT 

REFUSED TO PART WITH THE SKATES FOR EVEN 

A SHORT TIME. THEN THE BOYS POOLED THEIR 

MONEY AND HUNTED EVERY HARDWARE STORE 

IN TOWN. THEY THOUGHT THEY COULD GET A 

PAIR FOR ABOUT A DOLLAR BUT FOUND THAT 

NONE HAD BEEN STOCKED. THERE WERE A FEW 

PEOPLE WHO BROKE UP THE ICE, WRAPPED IT 

UP IN PAPER, AND TOOK IT HOME FOR 

SOUVENIRS. 

OFFICIAL TEMPERATURES WERE BELOW 32

DEGREES FOR 7 HOURS, BUT AT THE KIOSK FOR,

APPROXIMATELY 12 HOURS. NEVER BEFORE IN 

HISTORY, OR SINCE, HAS SAN DIEGO 

EXPERIENCED SUCH BITTER COLD. 

WEATHER BUREAU FORECASTER E. HERBERT 

NIMMO EXPLAINED IT THIS WAY: 

“THE WEATHER REPORTS FROM THE GULF AND 

ATLANTIC STATES BEING MISSING, WE ARE 

FORCED TO REPORT SOMEWHAT TO 

SPECULATION IN ACCOUNTING FOR CONDITIONS 

HERE. BUT I FEEL PRACTICALLY CERTAIN THAT 

THE EXTENSIVE HIGH BAROMETER AREA IN THE 

NORTHWEST HAS BEEN RETARDED IN ITS 

EASTWARD MOVEMENT BY EXCEPTIONAL 

CONDITIONS IN THE EAST. A LOW BAROMETER 

AREA HAS ALSO MADE ITS APPEARANCE OVER 

NORTHERN ALBERTA MONDAY AND IS MUCH 

STRONGER THIS MORNING. THIS, OF COURSE,

TENDS TO FORCE THE HIGH, COLD AREA 

SOUTH.” 

V. PRECIPITATION

Since rainfall in the San Diego area is 

generally a late fall through early spring 

phenomenon, statistics are normally 

presented on a “water year” basis, as 

opposed to a calendar year format. The 

water year displays a more coherent picture 

of rainfall data. The NWS computes the 

water year from July 1st through June 30th. 

The average annual precipitation downtown, 

based on a continuous record from July 

1850 through June 2005, is 10.00 inches. 

The current and official 30-year average 

(1971 to 2000) is 10.77 inches. This long 
8

term precipitation record has an unusual 

statistic included in it. The entire 

measurable amount of precipitation at the 

official station location has fallen in the 

form of rain. This means that snow, ice 

pellets, and hail have never accounted for 

more than 0.005 inches of their water 

equivalent. 

San Diego experiences a large range in 

seasonal precipitation. The wettest year 

since 1850 occurred in 1883 to 1884, where 

a record 25.97 inches of rain fell. 

Interestingly, this wet year was preceded by 

an exceptionally dry year, in 1882 to 1883, 

only 4.92 inches fell; a difference of 21.95 

inches in one year. The driest year on 

record is 1960 to 1961, with only 3.46 

inches of precipitation falling all season. 

The recent heavy precipitation year of 2004 

to 2005 had 22.49 inches of rain, and was 

the third wettest season on record. 

Most of the rain falls during the months of 

November through March. Statistically, 

during the 1850 to 2005 period, the wettest 

month is February (1.99 inches); but during 

1971 to 2000 “normal,” January is the 

wettest month with 2.43 inches. 

Approximately 10 percent of the total 

seasonal rainfall normally occurs from May 

through October and approximately 2 

percent occurs during the three-month 

period from June through August. 

Heaviest rains are associated with storms 

approaching California from the west, which 

frequently tap into a moisture supply from 

the subtropics. Heavy rains, up to 3.23 

inches in a calendar day, have been recorded 

in the downtown area. The probable 

maximum precipitation at San Diego, based 

on statistical analysis, is included as 

reference. 

Thunderstorms

Thunderstorms are rare for San Diego, but 

when they happen it is generally during 

winter. Sometimes they produce small hail 

and gusty winds. The number of 

thunderstorms the area receives varies 

greatly throughout the year, but the average 

is 3. Some years will produce no 

thunderstorms, but in years like 1936 there 

were 11. Most thunderstorms have just one 

or two claps of thunder and are short lived, 

although some have constant rumbling for 

several hours. The longest thunderstorms 

lasted for almost 8 hours on two different 

dates: May 20, 1920 and December 8, 1926. 

About every other summer, a thunderstorm 

will work its way off the mountains and 

quickly move through the downtown area. 

This type of occurrence is associated with 

easterly flow aloft that develops almost 

yearly, during the summer season. The 

airmass is generally not unstable enough to 

sustain a thunderstorm for more than an 

hour, which does not allow them to move 

past the valleys and into the coastal areas of 

San Diego county. 

 When the clouds appear 

 Like rocks and towers, 

 The earth’s refreshed 

 By frequent showers. 

Snowfall History for San Diego

Many years ago there was a small village, 

where only several hundred people lived in 

adobe houses, located on a sand flat at the 

foot of a hill. This was San Diego in 

December, 1847, which is the area we now 

call Old Town. Light snow had fallen over 

the nearby hills but heavier amounts of snow 

had fallen to the east and near the 

mountains. There was even a possibility 
9

that a few flakes fell in town but details of 

this storm lived only in the memories of 

early settlers. 

Weather observations were started in July, 

1849, followed shortly by a newspaper, 

which greatly helped documentation and 

reporting of the next storm, “The Great 

Storm of January, 1882.” 

This storm was accompanied by a blustery 

surge of very cold air and moved into San 

Diego County on the 12th but has no entries 

for snow. From the Daily Journal for 

January 12, 1882: “At a few minutes before 

7 am light rain began falling accompanied 

by sleet for a few moments at 7:20 am.” 

And from a U. S. Signal Service report: “On 

the morning of the 14th snow flakes were 

observed melting as fast as they fell, a 

phenomenon never before noted at this 

station.” Sleet also fell at 8 am at the 

residence of Mr. G. W. Barnes. 

It snowed quite heavily outside of town, and 

by noon there were 3 inches in the El Cajon 

Valley, 4 inches on Poway Grade, and 1 

inch in the valley. Measurable snow fell in 

Del Mar and it was reported that roofs of 

houses in the San Pasqual Valley caved in 

from the weight of the snow. Snow varying 

in depth from 2 to 5 inches was reported in 

other areas within 15 to 25 miles of the 

station and Julian had 15 inches. It was the 

coldest storm on record and magnificent 

white hills awed early residents. The snow 

line had never before come so near the bay, 

according to residents, some of whom had 

lived in the area for 40 years. 

The biggest story, however, was the severe 

unabated storm in the mountains. It started 

snowing in Campo at 7 am on the 12th, and 

by 3 pm there was a foot on the ground and 

the telegraph lines were down. Snow 

measured 20 inches on the 13th, and brisk 

easterly winds prevailed, causing severe 

drifting. Snow was up to 2 feet deep on the 

14th, and finally ended at 1:40 pm on the 

15th. After nearly four days there was 3 feet 

of snow on the ground, many drifts 8 feet 

deep, hundreds of birds killed, and stock 

suffered severely. The roads were still 

impassable on the 18th due to the deep 

drifts. Snow softened and melted very 

slowly but heavy rains on the 24th and 25th 

began to wash away the snow rapidly, and 

only then could roads be opened. 

Actual snow flurries fell at Lindbergh Field 

from 4:10 to 5:30 am on January 21, 1937, 

and were reported by a Weather Bureau 

Observer on duty. This was the only time 

that snow in flake form had fallen at the 

airport but it was not even given the dignity 

of being entered in the record books because 

it did not happen at the official station. 

Residents in the eastern and northern parts 

of the city awakened to find those delicate 

snowflakes gently floating down outside 

their windows. Some graupel was also 

reported. Snow was on the roofs for as long 

as an hour and in some areas there was 

enough for small snowballs. Meanwhile, 

back at the Federal Building at Union and F 

Streets where the official weather observer 

was on duty, the phone began to ring with 

inquiries from the newspaper and residents. 

It was reported that, “he craned his neck and 

scanned the horizon, but not a snowflake 

was in sight.” That was official and that is 

what was recorded. At that time, the U. S. 

Weather Bureau staffed two offices in San 

Diego but only the City Office observations 

were entered in the record books. 

The weakest snow storm occurred on 

February 11, 1946, as early morning 

showers were followed by icy winds (up to 
10

72 mph in the mountains) and cold rain. A 

few brief snow flurries were reported in 

several parts of the city. Lindbergh Field 

had no snow and only 7 hundredths of an 

inch of precipitation. 

“Blizzard Lashes San Diego County,” 

headlined the Tribune-Sun on January 10, 

1949, as winter arrived in Southern 

California, bringing wind, snow, hail, sleet, 

rain and blocked highways; a severe gas 

shortage resulted. 

Snowfall was the heaviest in history with 3 

feet at Mount Laguna, 18 inches at 

Cuyamaca, 12 inches at Julian and 4 to 8 

inches as low as 1000 feet. There was a 

light covering at Escondido, Spring Valley, 

and other points surrounding the city, which 

was enough for snowballs. A few patches 

were visible in the early morning hours 

within the city limits at Camp Miramar, 

Rose Canyon, Mt. Helix, East San Diego, 

North Park, La Jolla, Point Loma and El 

Cajon. Traffic was snarled in many areas. 

Howling winds accompanied the snowfall, 

and drifting snow closed major highways 

and secondary roads in the mountain areas. 

Wind speeds reached 75 mph at the Airways 

Communication Station. Power failures 

were scattered throughout the city during the 

night as winds gusted up to 40 mph. A party 

of eight Girl Scouts and five adults was 

marooned at their Cuyamaca camp. A plane 

crash took five lives and injured one as it 

smashed into a mountain near Julian. 

San Diego Gas and Electric announced a gas 

emergency for the second time in a week 

and asked for cooperation in conserving gas 

by using it only for cooking and water 

heating. They later eased the request by 

asking that heating be restricted to one room 

in each house but warned that users might be 

asked to eliminate all use of gas for heating 

to avoid a complete shutdown of gas service 

in some sections. 

This was the only time in history that snow 

had fallen in the city on successive days. 

Lindbergh Field reported snow pellets from 

6:55 to 8:20 on the evening of the 10th, with 

heavy snow pellets from 4:45 to 5:00 the 

morning of the 11th. 

January, 1949, besides the blizzard and 

snow in the city, is also the coldest month on 

record. Days and nights were both cold, 

with the lowest temperature dipping to 29 

degrees. 

Palomar Airport, north of San Diego and 

near Carlsbad, had a 10 am temperature of 

33 degrees with 2 inches of snow on the 

ground. This was on December 13, 1967, 

and was the second major storm to bring 

winter weather to Southern California. 

The snow was preceded by numerous 

thunderstorms, hail, lightning, icy winds, 

and rain. Marble size hail fell at Palomar 

Mountain State Park with smaller hail 

reported in other areas. Snow accumulated 

to a depth of 2 feet at Palomar Mountain, 12 

to 18 inches at higher elevations, and 6 

inches at Temecula. 

Strong, gusty winds accompanied the storm, 

and all the schools in Fallbrook, Julian, and 

Mountain Empire Unified School Districts 

closed. Chains were required on most 

mountain highways, but none was 

completely blocked. In an effort to keep 

roads open, the County Engineer put 65 

units, including all snowplows and graders, 

in to operation. Borrego Springs had 3 

inches of snow, Anza Borrego State Park 

had 4.5 inches, and a few flurries mixed 

with hail and cold rain fell at El Centro. 
11

Snow covered most areas including Del 

Mar, Encinitas, Vista and La Jolla. Up to 5 

inches fell in Fallbrook. Winds were calm 

that night as big snowflakes floated down 

over North Park, East San Diego, 

Clairemont, University City, and along 

Interstate 8 above Mission Valley. San 

Diego Police Sgt. John E. Mansfield said 

from his traffic control helicopter, “The 

whole city of San Diego was white.” 

Students at Kearny High School left 

classrooms to go outside and throw 

snowballs. Snow in pellet form fell at 

Lindbergh Field from 7:50 to 8:50 am. 

There were so many minor traffic accidents 

that law enforcement officials were forced to 

tell people to move on and file reports later. 

High winds created numerous brief power 

outages. Telephone switchboards were 

jammed at both the Evening Tribune and the 

Weather Bureau by excited people calling in 

to report snow in their areas. 

San Diego almost had a ‘White Christmas’ 

as a cold winter storm entered the region on 

December 24, 1987. Snow fell in the 

Laguna Mountains and chains were required 

on all vehicles. Snow flurries or flakes were 

reported during the late afternoon from 

many areas, including some within the city 

limits. Residents of Descanso and Jamul 

played in a winter wonderland with snow 

covering the ground and snowballs filling 

the air. Lindbergh Field did not even report 

a sprinkle. 

A Winter Storm Warning was in effect on 

January 17, 1990 as a cold and windy storm 

reached Southern California, causing rapidly 

dropping snow levels. Mt. Laguna reported 

14 inches of snow on the ground, which 

covered most of the mountain roads. Snow 

flakes or flurries were reported within the 

city limits, including several coastal 

communities, but once again Lindbergh 

Field did not report snow. 

Genuine snow, whether it is in the form of 

sleet, ice pellets, snow pellets, graupel, or 

flakes, has fallen in the city on at least 10 

days, with only 3 of them considered 

official. 

Tropical Cyclones

A tropical cyclone, by definition, is a 

rotating storm that originates over the 

tropical oceans. The tropical cyclone season 

in the Pacific Ocean is from the end of May 

through November, but can start as early as 

May first and last into December. It is rare 

for downtown San Diego to experience the 

direct effects of a tropical cyclone; there are 

only 16 documented cases in which the city 

has had a firsthand account of this type of 

atmospheric phenomenon. The effects of 

tropical cyclones on the city of San Diego 

are normally minor since most cyclones 

move in a westerly direction and dissipate 

without incident in the Pacific Ocean. The 

moisture left over from these storms can be 

collected by mid latitude troughs and 

advected over Southern California, 

producing the few significant summer rain 

events of downtown San Diego. In the 

mountains, however, the tropical moisture 

will increase the chance for thunderstorms 

which can cause heavy warm rains and flash 

flooding. 

The only tropical cyclone known to produce 

estimated hurricane-force winds on the 

California coast affected San Diego on 2 

October 1858. Wind damage was largely 

confined to coastal areas but heavy rains 

were felt inland and produced some 

flooding. The path of the storm exposed the 

entire coastline from San Diego north to the 
12

Long Beach areas to estimated tropical 

storm-force winds. This path has more 

destructive potential than the 1939 tropical 

storm that struck a much more limited 

section of coastline. Sustained category 1 

hurricane winds (approximately 70 knots) 

and 994 mb were unprecedented in San 

Diego. No evidence exists suggesting 

comparable or stronger winds in U. S. Army 

records dating back to 1849. 

A few tropical storms and depressions have 

brought copious amounts of rain to Southern 

California. One in particular, tropical 

cyclone Kathleen, hit the area at tropical 

storm strength (winds of 34 to 63 knots) on 

the 9th through the 12th of September, 1976. 

Kathleen caused flooding mainly in the 

deserts of Southern California and set daily 

rainfall records. At Lindbergh Field, new 

records were set for September 9th and 10th, 

at 0.09 inches and 0.87 inches, respectively. 

 Evening red and morning gray 

 Help the traveler on his way; 

 Evening gray and morning red 

 Bring down rain upon his head. 

VI. WIND

Reliable wind observations date back to the 

mid 1880s and have varied in instrument 

elevation from the current 20 feet to a high 

of 102 feet. A sea breeze is common in the 

late morning through the evening, because 

of the Pacific Ocean influence. The 

mechanism that drives this wind is the 

differential heating between the ocean 

surface and the land. In the afternoon a 

westerly flow at an average speed of 10 mph 

results. The overall yearly average is 7 mph 

from the west-northwest. The greatest peak 

gust of 64 mph from the west last occurred 

in January of 1988. 

Santa Ana Winds

Santa Ana winds are generally defined as 

warm, dry winds that blow from the east or 

northeast. These winds occur below the 

coastal mountain ranges of Southern 

California and often blow with exceptional 

speed in the Santa Ana Canyon (the canyon 

from which the wind derives its name). 

Forecasters usually reserve the use of "Santa 

Ana" for winds greater than 25 knots. 

The complex topography of Southern 

California combined with various 

atmospheric conditions creates numerous 

scenarios that may cause widespread or 

isolated Santa Ana wind events. 

Commonly, Santa Ana winds develop when 

a region of high pressure builds over the 

Great Basin (the high plateau east of the 

Sierra Mountains and west of the Rocky 

Mountains, including most of Nevada and 

Utah). Clockwise circulation around the 

center of this high pressure area forces air 

down the mountain slopes from the high 

plateau. Due to compresssional heating, as 

air descends it warms at a rate of 

approximately 5 degrees Fahrenheit per 

1000 feet. As well as warming, the 

descending air dries, leaving an airmass with 

relative humidity values in the teens. This 

dry, warm, air is characteristic of the Santa 

Ana conditions and these conditions are 

often linked to high fire danger in Southern 

California. 

Santa Ana winds commonly occur between 

October and February; December has the 

highest frequency of events. Summer events 

are rare. Winds are typically from the 

northeast, at speeds of 35 knots through and 

below passes and canyons, with gusts to 50 

knots. Stronger Santa Ana winds can have 

gusts greater than 60 knots over widespread 

areas, and gusts greater than 100 knots in 

favored areas, such as the Santa Ana 
13

Canyon. Frequently, the strongest winds in 

the basin occur during the night and 

morning hours due to the absence of a sea 

breeze. The sea breeze, which typically 

blows onshore daily, can moderate the Santa 

Ana winds during the late morning and 

afternoon hours. 

VII. PRESSURE

The mercurial barometer at Lindbergh Field, 

which was removed when ASOS was 

commissioned, had its ivory point at an 

elevation of 28 feet above sea level. The 

average station pressure is 1014.3 millibars. 

The twice daily symmetrical swing of the 

atmospheric pressure is rather striking, with 

maxima occurring at about 10 am and 10 pm 

and minima at about 4 am and 4 pm. These 

can be described, in a general fashion, as 

daily “pressure tides.” As the tides are 

repeated at the same solar time day after 

day, it is beyond doubt that they are caused 

in some way by the sun. The low pressure 

tide at about 4 pm results from air aloft 

being heated and rarified. The reasons for 

the other tides are not well understood, but 

most likely depend on delayed heating and 

cooling as well as ionization at upper levels. 

The highest sea level pressure ever recorded 

in the downtown area is 30.53 inches of 

mercury on February 17, 1883. The lowest 

is 29.37 inches of mercury on March 3, 

1983. 

 When the glass falls low, 

 Prepare for a blow; 

 When it rises high, 

 Let all your kites fly. 

 When the hollow winds begin to blow, 

 The clouds look black, the glass is low. 

VIII. RELATIVE HUMIDITY

Humidity is an indicator of the amount of 

water vapor in the air. Relative humidity is 

the ratio between the amount of water vapor 

actually in the air at a certain temperature 

and the theoretical amount of water vapor 

present when the air is saturated at that same 

temperature. This is usually expressed as a 

percentage. 

Relative humidity averages 69 percent at 

San Diego on an annual basis. The average 

daily maximum relative humidity is 82 

percent, generally occurring in the early 

morning hours around sunrise. The average 

daily minimum is 54 percent, usually 

occurring around noon. 

During May through October, humidity is 

higher than the annual average by about 10 

to 20 percent, while during November 

through February, humidity is generally 

lower than the average by about 10 to 20 

percent. Moist conditions are commonplace 

in San Diego. Near 100 percent relative 

humidity is typical for the late nights and 

early mornings of spring and summer, when 

there is a strong marine layer influence. 

Very low relative humidity is rare in San 

Diego but, when it occurs, a Santa Ana wind 

condition is often present. With strong 

offshore flow and downslope winds, the air 

dries rapidly as the land breeze develops. 

Relative humidities of less than 5 percent 

have been recorded in the city with this type 

of situation. 

IX. AIR QUALITY

The name “Smog” originated in 1905 and 

was used to describe a combination of 

smoke and fog. More recently it has been 

applied to a mixture of pollutants from 

automobiles and industrial wastes, and their 

accumulated reaction products. Rapid 

growth and increasing population, as well as 
14

the widespread use of automobiles after 

World War II, started an escalation of 

smoggy days. Geography, topography, 

climate, population increase, and a high 

concentration of vehicular traffic are key 

elements to the distribution and 

development of pollutants. 

Precursor emissions, mainly oxides of 

nitrogen and hydrocarbons, are generated in 

the populated coastal areas and drift inland 

with the daily sea breeze and primarily 

affect inland sections. On some occasions, 

precursors (or even ozone) are generated in 

the heavily populated Los Angeles area, 

carried out over the ocean during a mild 

Santa Ana wind condition, and then picked 

up by the sea breeze which brings them back 

onshore and into San Diego. It has been 

estimated that about 60 percent of these 

precursors are generated by cars and trucks. 

For San Diego, ozone remains the major air 

pollution problem. It results from complex 

reactions that occur in the presence of 

sunlight; ozone is the primary component of 

photochemical smog. In addition to 

pollution advection over San Diego, it is 

common for a layer of warm dry air to lie 

above a moist cool marine layer which 

creates a temperature inversion. The 

temperature inversion prevents polluted air 

from rising and mixing with the air above, 

thus causing hazy conditions. 

Due to the drastic increase in pollution, 

monitoring began in 1955, followed by air 

pollution programs, which are regulated on 

both state and federal levels. All air quality 

reports in the United States are based on the 

Pollutant Standards Index. For ground level 

ozone, values greater than 75 on the index 

exceed the State Standard for clean air and 

values greater than 100 exceed Federal 

Standards. At a value of 138, a Health 

Advisory is issued. When this level is 

reached the air is considered unhealthy, with 

15 parts of ozone per hundred million parts 

of air. At 200, a Stage 1 Alert is reached; 

and at 275, a Stage 2 Alert is declared. 

These stages are considered very unhealthy. 

Air quality was the worst in the 1960’s and 

1970’s prior to passage of the Clean Air Act. 

In San Diego, Stage 2 Alerts were reached 

once in 1978, and three times in 1979. 

Stage 1 Alerts were also frequent, with 11 in 

both 1978 and 1979. San Diego has not had 

a Stage 2 Alert since 1979, or a Stage 1 

Alert since 1991. 

The Federal Standards were violated on 90 

days in 1978 and 87 days in 1980. From 

there, the trend continues downward, with 

only 2 days above Federal Standards in 

1996. State Standards were violated 151 

days in 1978, but a record 192 days in 1981. 

After 1981, the general trend is downward, 

indicating improving air quality. In 2003, 

however, 23 days violated the State 

Standards, an 8 day increase over 2002. 

Pollutants play a very important part in our 

daily weather by not only causing hazy 

conditions but also being the nuclei for the 

formation of fog. Because of the improving 

air quality throughout the last few decades, 

the yearly number of days with either fog or 

haze reported has also decreased 

dramatically. 

X. SKY COVER, CLOUDS, FOG AND 

 HAZE

San Diego is a mostly sunny place with an 

average of 146 clear days per year. A clear 

day represents less than 4 tenths of the sky 

covered in clouds during the hours from 

sunrise to sunset. Approximately 117 days 

are considered partly cloudy (4 tenths to 7 

tenths sky coverage), and 102 days on 
15

average have cloudy skies. Most of these 

partly cloudy and cloudy days are due to the 

marine layer or “velo” cloud, as it was 

called many centuries ago. 

Fog that produces very low visibilities, 1⁄4 

mile or less, occurs an average of 22 days a 

year (1942 to 2005). This “dense fog” is 

usually caused by airmass advection of a 

shallow marine layer. The peak time during 

the year for dense fog is from October 

through February. Lower visibilities from 

fog, not considered dense, also occur during 

the winter season (December, January and 

February) and are mainly associated with 

rain. 

When visibilities are below 7 miles, an 

observer is required to report a restriction to 

visibility. If the restriction is not associated 

with water vapor and is not obvious, such as 

smoke or rain, haze is generally reported. 

Haze is fine dust or salt particles dispersed 

through a portion of the atmosphere. The 

particles are so small that they cannot be felt 

or individually seen with the naked eye, but 

they diminish horizontal visibility. During 

the period 1942 to 2005, the average annual 

number of days with haze is just over 151. 

This is normally associated with a 

dissipating marine layer where the low 

clouds have retreated but the particles in the 

air have not allowed the visibility to increase 

to 7 miles. 

 A summer fog for fair, 

 A winter fog for rain; 

 A fact most everywhere, 

 In valley and on plain. 

XI. COASTAL EDDY

During the spring and summer months, 

Southern California coastal areas and 

valleys experience many days with low 

clouds and fog in the early morning and late 

evening. At times, usually on the coast and 

less often in the valleys, there are days when 

the low clouds and fog persist into the 

afternoon and occasionally all day. A 

coastal eddy is often the cause when low 

clouds and fog last into the afternoon. In 

Southern California, coastal eddies are often 

generically referred to as Catalina Eddies 

(for the island that the coastal eddy forms 

about). 

A Catalina Eddy forms when upper level 

large-scale flow off Point Conception 

interacts with the complex topography of the 

Southern California coastline. As a result, a 

counter-clockwise circulating low pressure 

area forms with its center in the vicinity of 

Catalina Island. Catalina Eddy formation is 

accompanied by a southerly shift in coastal 

winds, a rapid increase in the depth of the 

marine layer, and a thickening of the coastal 

stratus. Catalina Eddies occur 

predominantly during the "stratus season" 

which is between April and September with 

a peak occurrence in June. 

The effects of the Catalina Eddy on the 

weather over Southern California can be 

quite dramatic from one day to the next. 

Usually, the increased thickness of the 

stratus clouds inhibits the typical 

morning/early afternoon dissipation. 

Coastal temperatures will be several degrees 

cooler than the day before since cloud cover 

reduces the amount of surface heating from 

the sun. Air quality may be improved since 

the Catalina Eddy disrupts the coastal 

inversion and allows pollutants to be mixed 

through a greater depth of the atmosphere. 

Also, increased cloudiness reduces 

photochemical reactions. On the downside, 

air travel may be affected due to reduced 

visibilities at airports. 
16

A typical Catalina Eddy will allow coastal 

low clouds and fog to persist into the 

afternoon. At other times, when the 

circulation of a Catalina Eddy is stronger, 

there is a deeper layer of low clouds that 

may reach as far inland as the intermediate 

valley of Riverside and San Bernardino 

Counties. When the Catalina Eddy is at its 

strongest, the depth of the low clouds may 

extend to 6000 feet and these clouds will 

move through the inland valleys and reach 

into the high deserts. 

XII. OUR CHANGING CLIMATE

“The American public is familiar on all 

sides with elaborate and detailed statements 

on the weather at a thousand and one resorts. 

If we may believe all we read in such 

reports, the temperature never reaches the 

eighties, the sky is flecked with just enough 

clouds to perfect the landscape, the breezes 

are always balmy, and the nights ever cool. 

There is possibly one place in the United 

States where such conditions obtain: a bit of 

country about forty miles square, at the 

extreme southwestern part of the United 

States, in which San Diego, California is 

located.” 

This quotation from General A. W. Greely, a 

former resident of San Diego and head of 

the United States Weather Service as Chief 

Signal Officer of the Army, was first 

published in the Climate of the United States 

in 1888. This was an accurate description of 

San Diego weather at that time, but slow and 

gradual changes have been taking place in 

the climate over the past several decades. 

Indications of these changes are most 

evident to those who follow the record high 

and low temperatures. This is where the 

most noticeable changes have occurred. 

Analyzing the maximum and minimum 

temperature record for 1874 to 2005, we 

find a general trend toward warming 

temperatures in San Diego. For each day of 

the calendar year there are four types of 

temperature extremes: maximum 

temperature, lowest maximum temperature, 

highest minimum temperature, and 

minimum temperature. The charts listing 

these temperatures can be found in the data 

section. Using the year for each type of 

record temperature as a reference, it 

becomes clear that the San Diego climate is 

not the same as it was when records began. 

During the first 26 years (1874 to 1899) of 

the temperature record, there were 43 days 

(11.7 percent) of the record maximum 

temperatures. The last 26 years (1980 to 

2005) have a much greater number of days 

with record maximum temperatures: 103 

days (28.1 percent). While at first this 

difference does not seem meaningful, when 

it is placed in conjunction with the lowest 

maximum temperature, it appears more 

significant. The lowest maximum 

temperature during the first 26 years 

occurred on 71 days (19.4 percent). This 

number dropped almost by one-third to 25 

days (6.8 percent) during the last 26 years. 

This demonstrates how maximum 

temperatures are becoming higher, and the 

frequency of relatively low maximum 

temperatures is decreasing. While the 

maximum temperature records show a shift 

towards warmer temperatures, the overall 

temperature trend towards higher average 

temperatures is greatly influenced by 

changing minimum temperatures. 

The effect of urbanization becomes apparent 

when we examine the highest minimum 

temperatures. During the first 26 years, there 

were 13 record days (3.6 percent). The last 

26 years had 268 days (73.2 percent). This 
17

is a phenomenal shift in highest minimum 

temperatures. This change is also seen in the 

records of absolute minimum temperature. 

In the last 26 years, there have been 6 record 

minimum temperature days (1.6 percent), 

while during the 1800’s there were 195 days 

(53.3 percent). This demonstrates the 

general trend towards warmer minimum 

temperatures during the more recent 

temperature record, in conjunction with an 

overall warming trend. 

Throughout the period of record, the city of 

San Diego has also been in transition. It 

started out with wood buildings, dirt streets 

and considerable open space. Now San 

Diego has expanded with streets of black 

asphalt, sidewalks of cement, and large 

paved parking lots, leaving very little open 

space. What has developed over the years 

of growth is termed an “Urban Heat Island,” 

or a rise in average temperatures (most 

noticeably the minimum temperatures) in 

the vicinity of a metropolitan area. The 

temperature of a densely constructed 

business district can be as much as 20 

degrees higher than the lowest observed 

suburban temperature on a calm clear night, 

but normally the difference is approximately 

7 degrees. This is most evident at night 

because solar radiation is more readily 

absorbed in the city by the buildings and 

paving materials that possess large heat 

storage and retain this heat through the 

afternoon. As night falls, these materials 

begin to release their heat slowly. By 

morning, this heat has still not entirely 

dissipated and the next day begins with a 

thermal edge. As the city grows, the 

temperature differential between it and rural 

communities will continue with cumulative 

effects. This will persist in the years to 

come, with only major global climate 

changes influencing this phenomenon. 

XIII. ACKNOWLEDGMENTS

We would like to give credit and thanks to 

Thomas E. Evans, III and Donald A. 

Halvorson for their work in compiling and 

writing the first edition, published in 

October, 1998. 

We appreciate the review and comments of 

San Diego National Weather Service staff 

Jim Purpura, Ivory Small, and Ed Clark for 

this edition of the paper. 

XIV. REFERENCES

Carpenter, F.A., 1913: The Climate and 

Weather of San Diego, California. San 

Diego Chamber of Commerce. 

Chenoweth, M. and C. W. Landsea, 2004: 

The San Diego Hurricane of October 2, 

1858. Bull. Amer. Meteor. Soc., 85, 1689-

1697. 

Court, A., 1980: Tropical Cyclone Effects of 

California. National Oceanic and 

Atmospheric Administration, National 

Weather Service, Technical Memorandum 

WR-159. 

Department of Sanitation and Flood Control, 

Tropical Storm Kathleen Storm Report, 

1976, San Diego County, California. 

Garriott, E. B., 1903: Weather Folk-Lore 

and Local Weather Signs. Government 

Printing Press, Washington, D.C. 

Humphreys, W. J., 1923: Weather Proverbs 

and Paradoxes. Williams and Wilkins 

Company, Maryland. 

Huschke, R.E., 1959: Glossary of 

Meteorology. American Meteorology 

Society, Massachusetts. 
18

Larson, J. L., 1977: Tropical Storm 

Kathleen. CALTRANS Report. 

Lee, A., 1976: Weather Wisdom. 

Doubleday and Company, Inc., New York. 

Lessard, A. G., 1982: Station Pressure for 

San Diego, California. Local study, Weather 

Service Office San Diego, California. 

Mitchell, J. M. Jr., 1961: The Temperature 

of Cities. U.S. Weather Bureau. 

National Oceanic and Atmospheric 

Administration, National Weather Service, 

Local Climatological Data, 1850-2005, San 

Diego, California. 

San Diego, California, Media Guide to 

Products and Services, 1996. 

San Diego County Air Pollution Control 

District. http://www.sdapcd.org/ 

San Diego, California, Station Logs. 

Small, I. J., 1995: Santa Ana Winds and The 

Fire Outbreak of Fall 1993. National 

Oceanic and Atmospheric Administration, 

National Weather Service, Technical 

Memorandum WR-230. 

Ulrickson, B. L., J. S. Hoffmaster, J. 

Robinson and D. Vimont, 1995: A 

Numerical Modeling Study of the Catalina 

Eddy. Monthly Weather Review, 123, 1364-

1373. 
19
20
21

NORMALS 

 San Diego, CA Latitude: 32° 44' 05" N Longitude: 117° 10' 07" W Elevation: 13 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT 

Normal Daily Maximum 65.8 66.3 66.3 68.7 69.3 72.2 75.8 77.5 77.0 74.Normal Daily Minimum 49.7 51.5 53.6 56.4 59.8 62.6 65.9 67.4 66.1 61.2 Normal Dry Bulb 57.8 58.9 60.0 62.6 64.6 67.4 70.9 72.5 71.6 67.Mean Wet Bulb (1984-2004) 51.4 52.4 54.2 56.1 58.8 61.0 64.5 66.0 65.0 61.Mean Dew Point (1984-2004) 45.1 46.6 49.0 51.4 54.9 57.7 61.6 63.1 61.8 56.9 Normal Number of Days with: Maximum ≥ 90° 0.0 * 0.1 0.2 * 0.5 0.2 0.3 1.3 0.7 

TEMPERATURE (F) Maximum ≤ 32° 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Minimum ≤ 32° 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Normal Heating Degree Days 227 176 160 90 47 10 0 0 1 12 

H / C Normal Cooling Degree Days 2 4 5 17 32 81 183 230 199 97 

Normal (percent) 67 69 70 69 73 75 76 76 75 72 Hour 04 LST 73 76 77 77 79 82 83 83 82 78 Hour 10 LST 58 61 62 61 66 69 70 70 67 63 Hour 16 LST 59 60 62 60 65 67 67 67 67 66 

RH 

Hour 22 LST 73 74 74 74 77 79 80 81 79 77 Normal Number of Days with: Fog 12.6 12.0 10.2 7.5 7.8 8.9 8.1 10.2 9.9 12.Dense Fog (visibility ≤ 1⁄4 mile) 2.1 2.1 1.1 0.6 0.3 0.5 0.4 0.4 1.4 2.3 Thunderstorms 0.2 0.4 0.4 0.3 0.0 0.2 0.2 0.4 0.2 0.3 

WEATHER Haze 10.5 10.3 9.0 8.6 10.8 14.3 15.5 15.9 15.0 14.PR Normal Sea Level Pressure (inches) 30.03 30.03 29.98 29.97 29.92 29.89 29.90 29.89 29.87 29.9

Normal Peak Gust (mph) 33.6 32.9 34.7 29.0 26.0 23.6 22.4 22.7 24.8 25.

WND Prevailing Direction (1979-2004) 300 300 300 290 300 290 300 290 300 300 

Normal (inches) 2.28 2.04 2.26 0.75 0.2 0.09 0.03 0.09 0.21 0.44 Normal Number of Days with: Precipitation ≥ .01 7.2 6.6 7.2 4.1 2 1.1 0.6 0.6 1.5 2.8 

PRECIP 

Precipitation ≥ 1.00 0.5 0.6 0.4 0.1 * 0.0 0.0 * 0.0 0.0 

S Normal (inches) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

 Normal refers to 1971 to 2000, unless otherwise indicated.  * indicates the value is between 0.00 and 0.05 
22

DAILY NORMALS OF TEMPERATURE, HEATING AND COOLING DEGREE DAYS AND PRECIPITA

December January 

Daily MAX MIN AVG Heating Cooling Precip Daily MAX MIN AVG Heating Cooling Precip Daily MAX MI

1 68 50 59 6 0 0.04 1 65 49 57 8 0 0.06 1 66 51 2 67 50 59 6 0 0.04 2 65 49 57 8 0 0.06 2 66 51 3 67 50 59 6 0 0.04 3 65 49 57 8 0 0.06 3 66 51 4 67 50 59 6 0 0.04 4 65 49 57 8 0 0.06 4 66 51 5 67 50 59 6 0 0.04 5 65 49 57 8 0 0.06 5 66 51 6 67 50 58 7 0 0.03 6 65 49 57 8 0 0.07 6 66 51 7 67 50 58 7 0 0.03 7 65 49 57 8 0 0.07 7 66 51 8 67 50 58 7 0 0.04 8 66 49 58 7 0 0.07 8 66 51 9 67 50 58 7 0 0.04 9 66 49 58 7 0 0.07 9 67 51 

10 67 50 58 7 0 0.04 10 66 49 58 7 0 0.07 10 67 51 11 66 49 58 7 0 0.04 11 66 49 58 7 0 0.07 11 67 51 12 66 49 58 7 0 0.04 12 66 49 58 7 0 0.07 12 67 51 13 66 49 58 7 0 0.04 13 66 50 58 7 0 0.07 13 67 51 14 66 49 58 7 0 0.04 14 66 50 58 7 0 0.07 14 67 51 15 66 48 57 8 0 0.04 15 66 50 58 7 0 0.08 15 67 51 16 66 48 57 8 0 0.04 16 66 50 58 7 0 0.08 16 66 52 17 66 48 57 8 0 0.04 17 66 50 58 7 0 0.08 17 66 52 18 66 48 57 8 0 0.04 18 66 50 58 7 0 0.08 18 66 52 19 66 48 57 8 0 0.04 19 66 50 58 7 0 0.08 19 66 52 20 66 48 57 8 0 0.04 20 66 50 58 7 0 0.08 20 66 52 21 66 48 57 8 0 0.04 21 66 50 58 7 0 0.08 21 66 52 22 66 48 57 8 0 0.04 22 66 50 58 7 0 0.08 22 66 52 23 66 48 57 8 0 0.04 23 66 50 58 7 0 0.08 23 66 52 24 66 48 57 8 0 0.05 24 66 50 58 7 0 0.08 24 66 52 25 66 48 57 8 0 0.05 25 66 50 58 7 0 0.08 25 66 52 26 66 48 57 8 0 0.05 26 66 50 58 7 0 0.08 26 66 52 27 66 48 57 8 0 0.05 27 66 50 58 7 0 0.08 27 66 52 28 66 48 57 8 0 0.05 28 66 50 58 7 0 0.08 28 66 52 29 65 49 57 8 0 0.05 29 66 50 58 7 0 0.08 29 66 52 30 65 49 57 8 0 0.05 30 66 51 59 6 0 0.08 Monthly 66.3 5331 65 49 57 8 0 0.06 31 66 51 59 6 0 0.07 

Monthly 66.3 48.9 57.6 7.4 0 10.77 Monthly 65.8 49.7 57.8 7.2 0 2.28 

Annual 70.8 58.1 64.4 0.6 0 10.77 
23

DAILY NORMALS OF TEMPERATURE, HEATING AND COOLING DEGREE DAYS AND PRECIPITATION 

March April 

Daily MAX MIN AVG Heating Cooling Precip Daily MAX MIN AVG Heating Cooling Precip Daily MAX MIN 

1 66 52 59 6 0 0.08 1 68 55 61 4 0 0.05 1 69 58 2 66 52 59 6 0 0.08 2 68 55 61 4 0 0.05 2 69 58 3 66 52 59 6 0 0.08 3 68 55 61 4 0 0.05 3 69 58 4 66 53 59 6 0 0.08 4 68 55 61 4 0 0.04 4 69 59 5 66 53 59 6 0 0.08 5 68 55 62 3 0 0.04 5 69 59 6 65 53 59 6 0 0.08 6 68 55 62 3 0 0.04 6 69 60 7 65 53 59 6 0 0.08 7 68 56 62 3 0 0.04 7 69 60 8 65 53 59 6 0 0.08 8 68 56 62 3 0 0.03 8 69 60 9 66 53 59 6 0 0.08 9 68 56 62 3 0 0.03 9 69 60 

10 66 53 60 5 0 0.08 10 68 56 62 3 0 0.03 10 69 60 11 66 53 60 5 0 0.08 11 69 56 62 3 0 0.03 11 69 60 12 66 53 60 5 0 0.08 12 69 56 62 3 0 0.03 12 69 60 13 66 53 60 5 0 0.08 13 69 56 62 3 0 0.03 13 69 60 14 66 53 60 5 0 0.08 14 69 56 63 2 0 0.02 14 69 60 15 66 53 60 5 0 0.08 15 69 56 63 2 0 0.02 15 69 60 16 66 54 60 5 0 0.08 16 69 57 63 2 0 0.02 16 69 60 17 66 54 60 5 0 0.08 17 69 57 63 2 0 0.02 17 69 60 18 66 54 60 5 0 0.07 18 69 57 63 2 0 0.02 18 69 60 19 66 54 60 5 0 0.07 19 69 57 63 2 0 0.02 19 69 60 20 66 54 61 4 0 0.07 20 69 57 63 2 0 0.02 20 69 60 21 67 54 61 4 0 0.07 21 69 57 63 2 0 0.02 21 69 60 22 67 54 61 4 0 0.07 22 69 57 63 2 0 0.02 22 69 60 23 67 54 61 4 0 0.07 23 69 57 63 2 0 0.01 23 70 60 24 67 54 61 4 0 0.07 24 69 58 63 2 0 0.01 24 70 60 25 67 54 61 4 0 0.07 25 69 58 64 1 0 0.01 25 70 60 26 67 54 61 4 0 0.06 26 69 58 64 1 0 0.01 26 70 60 27 67 55 61 4 0 0.06 27 69 58 64 1 0 0.01 27 70 60 28 67 55 61 4 0 0.06 28 69 58 64 1 0 0.01 28 70 60 29 67 55 61 4 0 0.06 29 69 58 64 1 0 0.01 29 70 60 30 67 55 61 4 0 0.05 30 69 58 64 1 0 0.01 30 70 60 31 67 55 61 4 0 0.05 Monthly 68.7 56.4 62.6 2.4 0 0.75 31 70 61 

Monthly 66.3 53.6 60 5 0 2.26 Monthly 69.3 59.8 
24

DAILY NORMALS OF TEMPERATURE, HEATING AND COOLING DEGREE DAYS AND PRECIPITATION 1

June July 

Daily MAX MIN AVG Heating Cooling Precip Daily MAX MIN AVG Heating Cooling Precip Daily MAX 

1 70 61 66 0 1 0.01 1 74 64 69 0 4 0.01 1 77 2 71 61 66 0 1 0.01 2 74 64 69 0 4 0.01 2 77 3 71 61 66 0 1 0.01 3 74 65 70 0 5 0.01 3 77 4 71 61 66 0 1 0.01 4 75 65 70 0 5 0 4 77 5 71 62 66 0 1 0.01 5 75 65 70 0 5 0 5 77 6 71 62 66 0 1 0.01 6 75 65 70 0 5 0 6 77 7 71 62 66 0 1 0.01 7 75 65 70 0 5 0 7 77 8 71 62 66 0 1 0.01 8 75 65 70 0 5 0 8 77 9 71 62 67 0 2 0.01 9 75 65 70 0 5 0 9 77 

10 71 62 67 0 2 0 10 75 65 70 0 5 0 10 77 11 72 62 67 0 2 0 11 75 66 71 0 6 0 11 77 12 72 62 67 0 2 0 12 76 66 71 0 6 0 12 77 13 72 62 67 0 2 0 13 76 66 71 0 6 0 13 77 14 72 62 67 0 2 0 14 76 66 71 0 6 0 14 77 15 72 62 67 0 2 0 15 76 66 71 0 6 0 15 77 16 72 63 68 0 3 0 16 76 66 71 0 6 0 16 77 17 72 63 68 0 3 0 17 76 66 71 0 6 0 17 77 18 72 63 68 0 3 0 18 76 66 71 0 6 0 18 78 19 73 63 68 0 3 0 19 76 66 71 0 6 0 19 78 20 73 63 68 0 3 0 20 76 66 71 0 6 0 20 78 21 73 63 68 0 3 0 21 76 66 71 0 6 0 21 78 22 73 63 68 0 3 0 22 76 66 71 0 6 0 22 78 23 73 63 68 0 3 0 23 76 67 72 0 7 0 23 78 24 73 63 68 0 3 0 24 77 67 72 0 7 0 24 78 25 73 64 69 0 4 0 25 77 67 72 0 7 0 25 78 26 74 64 69 0 4 0 26 77 67 72 0 7 0 26 78 27 74 64 69 0 4 0 27 77 67 72 0 7 0 27 78 28 74 64 69 0 4 0 28 77 67 72 0 7 0 28 78 29 74 64 69 0 4 0 29 77 67 72 0 7 0 29 78 30 74 64 69 0 4 0 30 77 67 72 0 7 0 30 78 

Monthly 72.2 62.6 67.4 0 2.4 0.09 31 77 67 72 0 7 0 31 78 

Monthly 75.8 65.9 70.9 0 5.9 0.03 Monthly 77.5 
25

DAILY NORMALS OF TEMPERATURE, HEATING AND COOLING DEGREE DAYS AND PRECIPITA

September October 

Daily MAX MIN AVG Heating Cooling Precip Daily MAX MIN AVG Heating Cooling Precip Daily MAX M

1 78 67 73 0 8 0 1 76 64 70 0 5 0.01 1 72 52 78 67 73 0 8 0 2 76 64 70 0 5 0.01 2 72 53 78 67 72 0 7 0 3 76 64 70 0 5 0.01 3 72 54 78 67 72 0 7 0 4 75 63 69 0 4 0.01 4 72 55 78 67 72 0 7 0 5 75 63 69 0 4 0.01 5 71 56 78 67 72 0 7 0 6 75 63 69 0 4 0.01 6 71 57 77 67 72 0 7 0 7 75 63 69 0 4 0.01 7 71 58 77 67 72 0 7 0 8 75 63 69 0 4 0.01 8 71 59 77 67 72 0 7 0 9 75 63 69 0 4 0.01 9 71 5

10 77 67 72 0 7 0.01 10 75 63 69 0 4 0.01 10 71 511 77 67 72 0 7 0.01 11 75 62 68 0 3 0.01 11 71 512 77 67 72 0 7 0.01 12 75 62 68 0 3 0.01 12 70 513 77 66 72 0 7 0.01 13 74 62 68 0 3 0.01 13 70 514 77 66 72 0 7 0.01 14 74 62 68 0 3 0.01 14 70 515 77 66 72 0 7 0.01 15 74 62 68 0 3 0.01 15 70 516 77 66 72 0 7 0.01 16 74 61 68 0 3 0.01 16 70 517 77 66 72 0 7 0.01 17 74 61 68 0 3 0.01 17 69 518 77 66 72 0 7 0.01 18 74 61 67 0 2 0.01 18 69 519 77 66 71 0 6 0.01 19 74 61 67 0 2 0.01 19 69 520 77 66 71 0 6 0.01 20 74 61 67 0 2 0.02 20 69 521 77 66 71 0 6 0.01 21 73 60 67 0 2 0.02 21 69 522 77 65 71 0 6 0.01 22 73 59 66 0 1 0.02 22 69 523 77 65 71 0 6 0.01 23 73 59 66 0 1 0.02 23 69 524 76 65 71 0 6 0.01 24 73 59 66 0 1 0.02 24 69 525 76 65 71 0 6 0.01 25 73 59 66 0 1 0.02 25 69 526 76 65 71 0 6 0.01 26 73 59 66 0 1 0.02 26 68 527 76 65 71 0 6 0.01 27 73 59 66 0 1 0.02 27 68 528 76 65 71 0 6 0.01 28 72 59 66 0 1 0.02 28 68 529 76 64 70 0 5 0.01 29 72 59 66 0 1 0.02 29 68 530 76 64 70 0 5 0.01 30 72 59 66 0 1 0.02 30 68 5

Monthly 77 66.1 71.6 0 6.6 0.21 31 72 58 65 0 0 0.03 Monthly 69.9 5

Monthly 74 61.2 67.6 0 2.6 0.44 
26

SAN DIEGO CLIMOGRAPH

0

0.5

1

1.5

2

2.5

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT 

Month

Rainfall (inches)

Monthly Rainfall Temperature
27

ANNUAL MEAN MAXIMUM, MEAN MINIMUM AND MEAN TEMPERATURE

45505560657075

18751879188318871891189518991903190719111915191919231927193119351939194319471951195519591963196719711975197919831987

Year

Temperature (degrees Fahrenheit)

Mean Max Temp Mean Temp Mean Min Temp30 Year Moving Average 30 Year Moving Average 30 Year Moving Average
28

MEAN MONTHLY TEMPERATURE

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1872 52.7 55.2 56.4 56.0 60.4 64.9 66.6 68.9 66.0 62.5 59.4 55.4 60.4 

1873 57.0 53.0 57.0 58.0 60.0 62.0 67.0 69.0 68.0 62.0 61.0 54.0 60.7 

1874 54.7 52.6 52.6 56.2 60.5 63.2 68.3 68.1 65.7 62.2 57.0 53.8 59.6 

1875 55.0 54.6 55.2 61.2 62.2 65.8 68.6 70.9 68.5 65.6 60.8 57.1 62.1 

1876 51.6 56.0 53.7 59.6 61.4 66.0 68.8 69.5 66.1 64.9 60.0 57.8 61.3 

1877 57.1 58.4 59.2 60.8 60.8 67.4 69.3 68.9 68.6 63.8 60.8 56.4 62.6 

1878 55.2 55.8 56.8 58.4 62.5 65.4 67.8 68.2 68.2 62.8 58.0 54.2 61.1 

1879 52.4 55.0 58.4 59.8 61.5 65.6 67.0 69.0 67.2 65.1 56.6 53.8 61.0 

1880 52.8 50.5 52.1 57.0 61.2 63.4 64.4 66.4 63.8 61.6 56.6 56.0 58.8 

1881 52.5 55.2 54.5 60.9 62.8 64.6 68.0 68.2 66.6 61.2 56.4 55.1 60.5 

1882 50.3 51.2 55.0 56.8 62.3 65.0 67.6 70.8 67.0 61.8 57.0 57.6 60.2 

1883 53.6 54.2 57.8 57.7 61.1 67.6 69.8 69.7 70.6 61.8 58.9 57.3 61.7 

1884 58.1 55.8 55.4 56.8 61.3 65.2 69.2 70.4 65.8 61.6 58.6 53.8 61.0 

1885 57.9 57.8 59.2 62.4 64.1 64.6 68.6 71.8 68.4 64.2 59.7 57.3 63.0 

1886 55.8 59.0 55.1 57.4 61.0 64.0 67.9 71.5 67.5 60.0 57.9 56.3 61.1 

1887 54.2 52.6 57.4 59.2 62.2 66.0 67.4 66.5 66.2 64.8 57.4 54.4 60.7 

1888 51.5 54.4 55.5 61.4 61.9 66.4 68.4 69.2 69.7 65.0 59.9 58.2 61.8 

1889 54.8 58.0 59.2 60.4 60.8 64.0 67.6 70.8 70.2 65.4 62.0 57.4 62.6 

1890 51.0 54.3 56.4 58.6 60.4 64.1 68.5 69.8 69.1 64.6 63.8 60.8 61.8 

1891 54.6 53.3 56.9 58.2 60.8 63.6 69.0 72.4 70.2 63.8 59.4 52.2 61.2 

1892 55.1 55.0 56.0 57.8 61.0 62.0 64.9 67.8 65.4 62.7 60.9 54.2 60.2 

1893 57.4 54.4 54.2 57.5 61.0 63.4 67.4 70.0 64.6 62.7 57.6 57.4 60.6 

1894 49.5 50.5 52.6 56.4 58.6 61.4 64.8 67.0 66.0 62.8 57.1 54.8 58.5 

1895 53.2 55.8 55.4 57.8 61.9 63.0 65.6 67.1 67.4 64.4 59.4 55.0 60.5 

1896 55.5 57.7 58.2 56.5 62.0 64.8 68.6 69.4 66.7 64.2 59.7 59.0 61.9 

1897 55.8 54.7 54.2 59.8 60.9 63.4 67.0 69.9 68.1 62.4 60.2 55.0 61.0 

1898 50.8 55.2 54.5 59.1 58.8 63.8 66.7 70.6 68.5 62.3 59.4 56.6 60.5 

1899 55.5 53.4 56.4 58.2 57.7 61.4 65.6 65.8 65.5 62.7 60.8 58.7 60.1 

1900 57.8 57.6 59.2 56.8 60.9 64.4 67.6 66.2 65.6 63.1 64.6 60.4 62.0 

1901 56.2 57.5 60.0 57.4 60.0 62.5 65.8 68.2 64.8 62.8 60.8 57.8 61.2 

1902 56.4 54.8 54.8 57.2 60.2 62.2 65.4 66.8 66.2 62.6 58.3 55.8 60.1 
29

MEAN MONTHLY TEMPERATURE

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1903 56.8 52.2 57.6 58.4 60.5 63.2 66.2 68.4 67.9 63.5 61.6 57.8 61.2 

1904 55.7 54.6 56.4 58.9 60.5 64.5 66.7 71.0 70.2 66.8 64.2 58.8 62.4 

1905 58.1 59.0 59.6 59.1 59.9 62.7 65.2 67.4 66.4 63.8 59.2 56.0 61.4 

1906 54.6 58.0 57.8 58.2 60.0 64.8 68.7 68.5 68.2 65.4 58.2 56.4 61.6 

1907 52.8 60.1 56.6 59.4 60.8 62.9 68.1 67.2 65.1 64.9 61.2 57.8 61.4 

1908 56.9 54.0 56.8 59.4 57.4 60.1 66.8 68.0 66.6 61.6 57.8 53.8 59.9 

1909 54.2 54.2 54.5 59.0 59.8 62.6 65.2 68.6 66.6 63.8 57.2 53.8 60.0 

1910 52.2 52.9 57.2 61.7 61.1 62.0 67.0 67.8 67.8 64.0 58.7 56.2 60.7 

1911 56.2 52.2 58.0 57.7 59.3 62.4 66.2 67.4 66.2 63.0 61.7 53.4 60.3 

1912 57.0 56.2 55.2 56.1 60.6 63.2 66.9 66.4 65.8 63.3 61.2 54.1 60.5 

1913 50.6 53.4 55.1 58.0 59.7 62.8 68.2 68.9 70.3 65.5 60.8 55.4 60.7 

1914 56.3 57.4 61.4 61.4 60.2 63.8 65.8 66.2 66.0 66.0 64.4 54.6 62.0 

1915 55.2 55.4 59.4 59.7 60.6 64.8 67.5 69.5 66.4 62.8 59.6 55.6 61.4 

1916 52.5 56.4 59.2 60.2 60.8 61.4 65.0 67.0 64.4 59.3 56.5 52.4 59.6 

1917 51.6 54.7 54.6 57.0 58.4 63.7 68.9 68.6 68.2 64.6 60.8 58.6 60.8 

1918 54.4 55.1 58.5 60.4 60.8 66.8 68.0 69.8 70.6 68.1 59.8 54.8 62.3 

1919 56.6 53.6 55.0 59.2 61.0 66.2 68.6 68.4 66.5 62.0 58.6 56.6 61.0 

1920 54.6 56.8 55.6 57.6 59.8 63.6 67.0 70.4 66.2 61.4 58.2 54.8 60.5 

1921 53.6 55.2 57.5 57.4 58.4 63.1 68.4 68.2 66.8 64.6 60.4 59.3 61.1 

1922 52.5 53.7 54.6 56.3 60.3 64.3 67.7 70.7 70.0 64.0 58.0 58.0 60.8 

1923 56.3 55.2 58.4 59.0 63.2 62.3 67.0 67.8 68.2 64.4 64.0 57.4 61.9 

1924 55.2 59.0 56.6 59.4 63.0 65.5 67.0 67.0 66.4 60.5 60.0 54.0 61.1 

1925 54.4 56.6 57.2 58.6 62.3 64.6 70.2 68.8 66.6 63.6 60.8 60.3 62.0 

1926 56.7 59.7 62.4 63.4 63.8 66.2 67.6 69.3 66.0 64.0 63.8 55.2 63.2 

1927 55.4 56.4 56.6 58.2 61.4 63.3 69.2 69.0 66.4 64.6 63.3 56.0 61.7 

1928 57.8 57.5 59.4 59.6 63.0 64.0 66.6 67.2 66.2 62.2 60.2 56.1 61.7 

1929 54.4 53.2 55.6 57.5 62.7 65.2 69.4 72.0 68.2 66.7 62.1 60.3 62.3 

1930 55.8 57.9 59.6 62.0 60.0 64.6 69.6 70.3 66.9 64.8 63.0 57.1 62.6 

1931 57.7 59.2 61.9 63.8 66.2 68.7 73.6 73.8 69.7 66.6 57.2 53.8 64.4 

1932 52.2 55.6 59.0 60.2 61.8 63.8 65.6 66.0 65.6 63.2 64.2 54.2 61.0 
30

MEAN MONTHLY TEMPERATURE

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1933 52.8 52.7 57.0 57.8 58.2 61.6 65.4 66.6 62.8 62.4 61.4 55.1 59.5 

1934 56.1 58.3 61.8 62.3 64.7 64.0 69.0 69.0 69.7 64.9 61.2 59.1 63.3 

1935 56.0 57.4 54.6 60.0 61.6 63.4 67.8 70.4 67.3 64.1 58.0 57.4 61.5 

1936 56.6 56.3 57.4 58.2 63.2 65.3 70.6 71.4 68.0 65.0 63.7 58.1 62.8 

1937 49.2 54.4 56.6 59.7 62.1 64.9 68.4 68.8 69.4 64.6 60.0 60.2 61.5 

1938 58.4 57.2 57.2 60.0 61.6 63.2 66.8 69.5 70.4 63.6 59.2 59.6 62.2 

1939 55.6 52.4 55.2 61.0 62.2 64.8 68.1 70.1 72.8 67.8 63.8 61.0 62.9 

1940 58.6 57.9 60.3 62.6 64.8 65.2 68.4 69.0 68.7 66.4 61.1 60.8 63.7 

1941 57.6 59.9 62.0 60.9 67.2 66.4 69.4 70.8 68.0 65.6 63.4 57.6 64.1 

1942 57.7 55.6 57.9 60.2 63.3 64.9 69.6 70.0 67.8 66.0 61.0 57.5 62.6 

1943 57.0 59.7 60.0 61.0 65.0 65.2 69.0 71.2 68.7 65.8 61.7 57.8 63.5 

1944 56.4 54.6 58.7 59.5 62.8 64.2 66.8 69.4 66.9 64.6 59.8 58.2 61.8 

1945 55.2 56.8 55.8 58.4 62.6 65.0 69.0 71.8 71.4 67.4 60.0 57.3 62.6 

1946 56.1 54.4 57.1 62.4 63.7 68.0 70.8 72.4 71.0 64.2 58.2 57.1 63.0 

1947 53.5 58.5 60.8 62.7 63.9 66.7 69.4 71.0 71.1 66.6 58.4 55.8 63.2 

1948 55.7 54.2 55.9 61.2 62.4 64.6 67.0 68.2 68.3 64.1 60.0 53.6 61.3 

1949 47.8 52.7 56.2 61.3 63.0 67.2 69.4 70.2 70.0 64.3 64.6 54.8 61.8 

1950 52.1 55.6 58.3 60.7 61.2 64.1 69.7 68.2 67.5 66.8 62.5 59.8 62.2 

1951 55.7 55.6 58.7 60.7 62.2 65.7 69.3 69.0 67.8 66.8 61.6 55.5 62.4 

1952 54.4 57.8 55.9 59.7 64.1 63.9 68.3 70.2 70.5 65.2 59.6 56.4 62.2 

1953 60.0 57.0 57.7 58.9 62.9 64.8 70.8 69.9 68.1 67.4 63.1 57.7 63.2 

1954 55.0 61.2 57.2 61.0 62.9 65.0 71.9 71.0 69.3 64.2 63.7 58.2 63.4 

1955 53.9 55.5 59.7 59.6 61.7 64.7 68.3 72.4 71.5 63.3 60.0 57.1 62.3 

1956 55.4 53.5 58.1 58.8 64.5 66.3 69.4 69.7 72.1 65.7 64.2 59.9 63.1 

1957 56.5 60.1 59.7 60.7 63.2 68.2 71.3 73.3 70.1 65.6 60.7 61.4 64.2 

1958 59.5 60.5 57.6 63.8 65.9 68.0 70.1 73.0 72.7 70.9 61.9 61.9 65.5 

1959 59.7 57.1 63.3 64.7 64.3 68.2 73.7 73.6 71.6 67.2 65.3 60.2 65.7 

1960 54.9 56.9 60.0 62.9 64.8 66.4 71.2 71.2 72.3 66.0 60.5 56.3 63.6 

1961 60.7 59.0 58.9 61.9 61.5 64.7 70.1 72.6 69.6 66.7 60.3 56.1 63.5 

1962 56.7 56.5 55.7 61.8 62.6 63.9 68.3 70.5 68.4 64.6 59.8 56.4 62.1 
31

MEAN MONTHLY TEMPERATURE

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1963 55.1 61.2 57.5 58.7 63.6 64.7 68.2 72.1 74.3 68.2 61.2 58.5 63.6 

1964 55.3 56.7 57.8 60.2 60.9 64.0 69.2 70.7 67.7 68.6 59.1 55.6 62.2 

1965 56.0 55.9 58.6 60.7 62.5 63.7 67.7 72.0 68.5 69.4 60.9 55.1 62.6 

1966 53.9 54.6 58.1 61.3 63.5 66.5 69.2 72.6 69.9 67.6 61.9 57.2 63.0 

1967 55.0 57.8 59.0 56.5 63.5 63.6 70.4 73.1 72.0 68.1 64.1 55.5 63.2 

1968 57.2 60.7 60.7 62.4 63.9 65.8 71.7 72.2 71.3 66.6 61.7 54.9 64.1 

1969 58.1 54.9 56.8 61.7 62.9 65.5 69.4 72.8 69.9 66.0 64.1 59.1 63.4 

1970 57.0 59.7 60.5 60.1 63.6 65.6 70.4 72.8 69.7 66.3 61.4 55.4 63.5 

1971 54.3 55.4 57.8 60.7 61.5 64.9 69.4 75.4 72.2 65.7 59.5 54.2 62.6 

1972 54.9 57.8 60.2 62.3 64.7 67.0 72.7 72.2 68.7 65.6 59.8 57.5 63.6 

1973 55.6 59.9 58.1 61.5 63.4 68.0 69.1 70.5 68.8 66.8 60.6 58.2 63.4 

1974 56.9 58.2 59.1 62.0 63.3 66.9 71.4 70.2 70.3 66.8 62.2 56.3 63.6 

1975 56.1 56.4 57.5 58.7 62.2 65.0 69.4 68.9 71.5 65.9 60.4 56.9 62.4 

1976 58.9 59.6 60.3 61.0 65.2 69.7 71.1 72.4 73.8 71.2 66.8 60.7 65.9 

1977 60.3 61.7 57.5 61.4 61.9 65.8 71.6 73.1 72.2 68.9 64.9 63.3 65.2 

1978 61.0 60.9 64.3 63.4 68.2 71.3 71.6 72.9 74.0 70.1 61.7 55.2 66.2 

1979 56.9 56.9 60.1 63.4 65.6 70.2 71.8 73.9 76.3 68.7 62.4 60.6 65.6 

1980 61.1 63.5 61.5 63.9 63.8 68.5 72.9 74.2 70.4 67.3 62.7 60.8 65.9 

1981 61.3 62.2 61.1 64.4 67.3 72.9 75.6 75.8 73.7 67.1 63.5 60.3 67.1 

1982 56.6 60.7 60.5 63.8 65.8 66.7 71.9 73.5 73.1 70.1 62.1 57.4 65.2 

1983 60.7 60.9 62.0 62.4 66.2 68.1 72.6 77.4 76.8 72.2 64.4 60.6 67.0 

1984 61.2 60.2 63.7 64.3 68.1 69.9 77.2 76.6 78.9 68.5 61.4 56.7 67.2 

1985 57.0 57.2 58.9 63.6 64.8 69.0 75.3 72.4 69.8 67.9 60.1 58.0 64.5 

1986 61.0 58.9 60.5 62.8 64.6 67.4 69.6 71.8 66.9 65.5 62.8 57.6 64.1 

1987 55.4 58.0 59.1 63.4 64.7 65.8 67.1 69.9 69.9 69.5 61.8 53.9 63.2 

1988 56.7 59.9 61.6 62.4 63.9 64.9 70.4 71.0 70.0 66.7 60.1 56.0 63.6 

1989 54.7 56.7 59.8 65.6 63.7 66.0 70.1 71.0 70.4 66.3 63.1 58.7 63.8 

1990 56.6 55.4 58.7 63.2 64.3 69.0 72.3 71.6 71.7 68.6 62.7 55.6 64.1 

1991 57.4 59.4 56.5 61.7 62.1 64.1 67.4 68.9 69.4 68.0 62.3 57.3 62.9 

1992 57.4 61.1 60.4 67.0 68.0 68.1 71.8 74.9 72.4 68.2 62.6 55.3 65.6 
32

MEAN MONTHLY TEMPERATURE

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1993 56.9 58.0 61.3 63.8 66.0 68.6 69.8 70.2 69.0 67.3 61.6 57.0 64.1 

1994 57.9 56.5 60.4 61.0 62.1 68.1 69.5 74.0 72.5 66.8 56.4 55.8 63.4 

1995 56.9 61.4 60.4 61.5 62.0 64.8 69.0 71.9 72 67.1 63.2 58.3 64.0 

1996 57.6 58.8 60.1 64.4 66.8 67.8 70 72.8 71 64.3 61.6 57.8 64.4 

1997 58.0 57.9 61.6 62.5 68.7 67.4 69.3 72.9 75.5 68.7 64.0 57.4 65.3 

1998 58.2 57.3 59.3 59.6 62.8 65.7 68.8 72.8 70.3 65.7 59.7 55.4 63.0 

1999 57.5 57.8 58.3 58.9 60.5 62.8 68.5 68.0 67.0 68.8 60.5 57.8 62.2 

2000 58.2 59.0 58.1 62.4 64.6 68.1 69.1 72.0 70.4 65.1 58.4 58.1 63.6 

2001 54.7 54.9 58.9 58.5 63.6 67.6 69.0 69.6 68.2 66.3 61.3 55.5 62.3 

2002 55.6 57.5 57.7 59.6 61.8 64.7 67.8 68.6 70.1 64.2 63.4 57.0 62.3 

2003 61.7 59.0 60.3 59.9 62.4 64.2 70.0 72.7 69.9 67.7 60.8 56.9 63.8 

2004 56.8 56.7 62.6 64.4 68.5 67.8 72.1 70.8 72.6 65.4 60.1 57.8 64.6 

2005 58.8 59.8 61.0 61.8 65.3 66.3 70.0 71.0 68.5 65.9 62.8 58.4 64.2 
33

TEMPERATURE READINGS OF 100 DEGREES AND HIGHER

BY SEVERITY CHRONOLOGICALLY

Temperature Date Temperature Date

111 September 26, 1963 100 September 25, 1989 

110 September 17, 1913 107 September 4, 1988 

107 September 4, 1988 104 October 3, 1987 

107 October 14, 1961 100 September 8, 1984 

106 September 21, 1939 100 June 16, 1981 

104 October 3, 1987 100 September 15, 1979 

104 October 22, 1965 101 June 10, 1979 

104 September 27, 1963 101 September 25, 1978 

104 September 1, 1955 103 September 23, 1975 

103 September 23, 1975 101 October 6, 1971 

102 September 11, 1959 104 October 22, 1965 

101 October 6, 1971 101 October 21, 1965 

101 June 10, 1979 104 September 27, 1963 

101 September 25, 1978 111 September 26, 1963 

101 October 21, 1965 107 October 14, 1961 

101 September 22, 1939 102 September 11, 1959 

101 September 22, 1883 104 September 1, 1955 

100 September 25, 1989 101 September 22, 1939 

100 September 8, 1984 106 September 21, 1939 

100 June 16, 1981 100 July 30, 1930 

100 September 15, 1979 110 September 17, 1913 

100 July 30, 1930 100 September 16, 1909 

100 September 16, 1909 101 September 22, 1883 

100 September 11, 1878 100 September 11, 1878 
34

TEMPERATURE READINGS OF 32 DEGREES AND COLDER

BY SEVERITY CHRONOLOGICALLY

Temperature Date Temperature Date

25 January 7, 1913 32 December 25, 1879 

28 January 6, 1913 32 January 31, 1880 

29 January 4, 1949 32 January 21, 1883 

30 January 5, 1949 32 December 26, 1891 

30 January 22, 1937 32 January 7, 1894 

31 January 13, 1963 28 January 6, 1913 

32 January 7, 1894 25 January 7, 1913 

32 December 26, 1891 30 January 22, 1937 

32 January 21, 1883 29 January 4, 1949 

32 January 31, 1880 30 January 5, 1949 

32 December 25, 1879 31 January 13, 1963 

 
35

MEAN YEARLY TEMPERATURES IN DESCENDING ORDER

Year Temp Year Temp Year Temp Year Temp 

1984 67.2 1967 63.2 1944 61.8 1909 60.0 

1981 67.1 1953 63.2 1883 61.7 1908 59.9 

1983 67.0 1947 63.2 1928 61.7 1916 59.6 

1978 66.2 1987 63.2 1927 61.7 1874 59.6 

1980 65.9 1956 63.1 1906 61.6 1933 59.5 

1976 65.9 1998 63.0 1937 61.5 2005 59.0 

1959 65.7 1946 63.0 1935 61.5 1880 58.8 

1992 65.6 1966 63.0 1905 61.4 1894 58.5 

1979 65.6 1885 63.0 1907 61.4 

1958 65.5 1939 62.9 1915 61.4 

1997 65.3 1991 62.9 1876 61.3 

1977 65.2 1936 62.8 1948 61.3 

1982 65.2 1877 62.6 1903 61.2 

2004 64.6 1945 62.6 1901 61.2 

1985 64.5 1965 62.6 1891 61.2 

1996 64.4 1942 62.6 1924 61.1 

1931 64.4 1930 62.6 1921 61.1 

1957 64.2 1889 62.6 1886 61.1 

1993 64.1 1971 62.6 1878 61.1 

1941 64.1 1904 62.4 1919 61.0 

1968 64.1 1951 62.4 1897 61.0 

1990 64.1 1975 62.4 1884 61.0 

1986 64.1 2001 62.3 1932 61.0 

1995 64.0 2002 62.3 1879 61.0 

2003 63.8 1955 62.3 1922 60.8 

1989 63.8 1918 62.3 1917 60.8 

1940 63.7 1929 62.3 1873 60.7 

2000 63.6 1999 62.2 1887 60.7 

1963 63.6 1964 62.2 1910 60.7 

1972 63.6 1938 62.2 1913 60.7 

1974 63.6 1950 62.2 1893 60.6 

1988 63.6 1952 62.2 1898 60.5 

1960 63.6 1875 62.1 1895 60.5 

1970 63.5 1962 62.1 1881 60.5 

1943 63.5 1925 62.0 1912 60.5 

1961 63.5 1914 62.0 1920 60.5 

1973 63.4 1900 62.0 1872 60.4 

1969 63.4 1923 61.9 1911 60.3 

1994 63.4 1896 61.9 1882 60.2 

1954 63.4 1949 61.8 1892 60.2 

1934 63.3 1890 61.8 1902 60.1 

1926 63.2 1888 61.8 1899 60.1 
36

 HIGHEST AND LOWEST DAILY TEMPERATURES FOR JANUARY

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 78 1898 53 1917* 57 1981* 35 1919*

2 80 1893 53 1910 60 1997 35 1919*

3 83 1943 51 1910 59 1997 34 1949

4 86 1969 51 1971 57 1991* 29 1949

5 80 1969 49 1913 63 X 1978 30 1949

6 78 1958* 45 X,Y 1913 61 1978 28 1913

7 81 1963* 49 1913 60 2003* 25 X,Y 1913

8 78 1983* 52 1888 60 1984* 33 1894*

9 85 1923 52 1913 60 1980 35 1891

10 88 X 1953 48 1949 61 1980 34 1888

11 83 1983 46 1949 62 1981 35 1913*

12 82 1986 50 1882 62 1981* 34 1882

13 83 1904 49 1882 62 1980 31 1963

14 82 1975* 54 1949 63 X 1980 35 1963

15 80 1976* 52 1882 61 1980 34 1888

16 86 1976 53 1987* 59 1993* 34 1947

17 86 1977 53 1933 61 1980 34 1888

18 81 2005* 55 1922* 59 2000 34 1888

19 87 2005 52 1917 59 1983* 39 1948*

20 80 1976* 52 1937* 58 2000* 33 1883

21 82 1912 50 1945 62 1976 32 1883

22 76 1910 52 1937* 57 1977* 30 1937

23 81 1953 51 1937 58 1981 37 1937

24 82 1951 51 1898 57 1983 35 1932

25 81 1951 51 1949 60 1969 36 1949*

26 82 2003 53 2001 59 1980 36 1949

27 83 1984 54 2001* 58 1980 37 1950*

28 83 1962 54 1922* 58 1980* 36 1948

29 81 1984* 53 2002* 60 1911 33 1880

30 82 1984 50 1975 61 1980* 34 1949

31 83 2003 53 1932* 58 1980 32 1880

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR

 
37

 HIGHEST AND LOWEST DAILY TEMPERATURES FOR FEBRUARY

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 84 1935 52 1923 58 1984* 36 1880

2 83 2000 51 1903 60 1884 35 1880

3 85 1963* 52 1978* 61 1935 37 1932*

4 82 2001* 53 1903* 57 1978* 37 1922

5 80 1963 52 1899 61 1978 38 1894*

6 83 1952 50 X 1899 62 1978 34 X 1899

7 88 1954 53 1949* 60 1920 37 1899

8 85 1954 54 1939 59 1978* 37 1883

9 77 1907 54 1908 60 1978 38 1929*

10 81 1988 52 1939 59 1970 34 X 1891

11 83 1988 53 1880 59 1981 34 X 1894

12 86 1943 55 1949* 59 2003 35 1880

13 87 1943 50 X 1949 60 1980* 35 1894

14 85 1943 51 1903 62 1980 36 1903

15 85 1943 52 1911 63 1980 35 1903

16 81 1981* 53 1932 63 1980 34 X 1911

17 84 1930 55 1898 62 1980 36 1894*

18 80 1981* 54 1918* 63 1980 37 1894*

19 90 X 1995 53 1882 61 1980 38 1955*

20 81 1982 54 1890 61 1980 37 1882

21 83 1981 53 1922 61 1980 39 1953*

22 87 2002 55 1967 59 1977* 38 1897

23 85 1954 53 1953 59 1983* 38 1887

24 89 1921 55 1987 60 1982 38 1897*

25 82 1926 55 1913 58 1989* 41 1956*

26 87 1926 55 1911* 58 2005 38 1894

27 83 1883 53 1911 61 1988* 39 1876

28 83 1901 56 2001* 64 X 1978 40 1890

29 74 1924 58 1892* 58 1988 45 1996*

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
38

HIGHEST AND LOWEST DAILY TEMPERATURES FOR MARCH

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 82 1901 56 1915* 63 1901 41 1888

2 78 1994* 54 1886 60 1978 39 1971

3 79 1931 51 X 1894 59 1989* 38 1894

4 85 1987 52 1894 60 1884 39 1894

5 86 1899 56 1896* 60 1987 36 X 1894

6 83 1899 56 1893 60 1905 38 1880

7 88 1914 57 1935* 59 1905 41 1891

8 85 1996 58 1925* 60 1983 39 1882

9 85 1934 54 1893 60 2004 42 1939*

10 85 1997 54 1876 59 1983 40 1935

11 88 1959 52 1922 62 1983* 40 1935*

12 84 1947* 55 1917 62 1983 38 1922

13 87 1994 55 1969* 61 1984 40 1917*

14 83 1951 53 1881 59 2003* 38 1898

15 80 1978* 57 1895 59 1993 39 1880

16 91 1978 54 1881 60 1980 38 1895

17 93 1978 56 1922* 59 1993 40 1881

18 82 1960* 55 1898 64 X 1978 41 1920

19 86 1997 56 1913* 62 1978 39 1880

20 88 1997 54 1894 62 1978 42 1898*

21 90 1931 56 1919* 61 1978 37 1894

22 82 1887 57 1909 61 1978 38 1894

23 88 1926 55 1929 60 1993* 40 1898*

24 85 1896 55 1913* 60 1993* 43 1929*

25 89 1988 56 1936* 62 1984 41 1880

26 93 1988 55 1898 62 1984 41 1936

27 82 1952 58 2002* 61 1984* 41 1880

28 95 1879 58 1935* 62 1978 41 1920

29 99 X 1879 53 1998 63 1978 43 1884

30 82 2003 56 1905* 62 1879 39 1875

31 84 1945* 57 1913 60 1983* 38 1905

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
39

HIGHEST AND LOWEST DAILY TEMPERATURES FOR APRIL

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 87 1985 57 1906 60 1981 41 1892

2 92 1960 58 1937* 60 1885 42 1906

3 89 1960 58 1898 59 1992* 41 1945

4 91 1971 56 1921 62 1992 43 1945*

5 95 1989 57 1922 63 1989 43 1945

6 98 X 1989 55 1875 65 1989 41 1875

7 93 1989 57 2001 64 1989 39 X 1875

8 82 1885 57 1922 61 2004* 41 1875

9 90 1968 58 1922* 61 2004 43 1893*

10 85 1968 58 1927* 65 1885 44 1935

11 90 1940 54 X 1912 62 2004* 44 1945*

12 93 1888 57 1912 62 1978 43 1927*

13 95 1940 57 1883 62 1978* 44 1911

14 91 1964 56 1921 62 1989 42 1883

15 90 1948 57 1917 60 1990* 44 1913*

16 87 1948 55 1917 61 1989* 45 1887*

17 82 1879 57 1917 62 1958 46 1967*

18 83 1914 55 1933 62 1992 44 1896*

19 85 1914 59 1902 62 1992 42 1880

20 93 1899 57 1883 63 1980 42 1896

21 88 1899 58 1925* 62 2004* 43 1896

22 95 1910 58 1999 62 1958 44 1878

23 96 1910 59 1899 64 1910 46 1963*

24 83 1995* 59 1899 62 1981 44 1880*

25 83 1992 59 1911* 63 1992* 44 1883*

26 88 2004 56 1900 63 1992 47 1932*

27 87 1986 57 1884 62 1992* 45 1883

28 88 1921 58 1933* 62 1982* 45 1900*

29 87 1996 57 1898 66 X 1992 43 1894

30 86 1996 57 1915 65 1981 46 1942*

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
40

HIGHEST AND LOWEST DAILY TEMPERATURES FOR MAY

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 81 1929 56 X 1915 65 1981 47 1932

2 93 2004 59 1913 63 1982* 45 X 1883

3 93 2004 58 1892 64 1980 45 X 1915

4 90 1953 59 1930 64 1992* 47 1930

5 96 1953 60 1921* 64 1984* 46 1910

6 87 1990 58 1899 65 1992 47 1892

7 85 1941 60 1930* 64 1997* 49 1964*

8 81 1941 60 1999* 63 1997 49 1965*

9 87 1984 57 1922 63 1997* 47 1908

10 85 1943 56 X 1933 65 1981 48 1933

11 83 1996 60 1933* 65 1992 47 1879

12 88 1979 57 1908 65 1992 46 1890

13 94 1979 60 1920* 64 1992* 48 1908

14 87 1956 60 1911* 65 1981 46 1880

15 91 1956 58 1953 65 1997* 46 1880

16 92 1956 61 1950* 65 1997* 45 X 1894

17 94 1956 61 1922* 65 1997 48 1894

18 87 1892 60 1899 65 1997 48 1880*

19 87 1943 60 1916* 65 1978 49 1894*

20 89 1883 60 1927* 65 1978 48 1896

21 85 1941 60 1903* 65 1997 49 1948

22 88 1893 60 1909 65 1997* 48 1878

23 82 1932 59 1917 65 1997* 48 1879

24 95 1896 58 1917 65 1984* 48 1879

25 98 X 1896 61 1917* 70 X 1896 49 1879

26 87 1896 60 1908 67 1896 50 1916*

27 84 1915* 61 1921* 66 1984* 50 1917

28 86 1997 61 1971* 66 1997* 52 1893

29 88 1978 61 1917* 67 1997* 52 1895

30 88 1879 59 1908 67 1997* 50 1878

31 94 1879 58 1899 67 1997 52 1906

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
41

HIGHEST AND LOWEST DAILY TEMPERATURES FOR JUNE

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 89 1879 62 1899* 67 1997 52 1916*

2 93 1879 58 X 1908 66 1997* 51 1967*

3 91 1919 62 1908 67 1981 51 1890

4 88 1898 62 1908* 66 2004* 50 X 1908

5 85 1890 61 1908 66 1993* 52 1880

6 93 1890 61 1899 67 1981 52 1948

7 92 1890 63 1917* 68 1981 53 1906

8 81 1890 63 1964* 67 1993 52 1950

9 93 1877 63 1971* 67 1984 54 1950*

10 101 X 1979 62 1901 68 1877 52 1892

11 98 1979 62 1899 70 1877 51 1892

12 90 1979 62 1901 72 X 1979 50 X 1894

13 90 1979 62 1911* 70 1979 50 X 1894

14 87 1917 62 1911 66 1984* 50 X 1943*

15 97 1981 64 1911 66 1984 52 1907*

16 100 1981 61 1908 69 1981 54 1897*

17 93 1957 62 1908 68 1981 52 1879

18 97 1957 63 1897 70 1981 54 1886

19 90 1957 63 1908 69 1981 53 1894*

20 90 1973 63 1908 67 1981* 53 1909*

21 88 1973 64 2003* 69 1981 54 1893

22 86 1978 63 1912 71 1981 55 1916

23 90 1978 61 1901 70 1981 51 1886

24 96 1931 64 1933* 70 1984* 53 1892

25 89 2000 65 1965* 71 1981 54 1943*

26 94 1990* 65 1920* 70 1981 52 1885

27 91 1990 63 1910 69 1984 52 1884

28 95 1980 63 1910 70 1976 56 1950*

29 84 1980 64 1902 70 1980 56 1910*

30 96 1985 64 1902 69 1984* 54 1910*

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
42

HIGHEST AND LOWEST DAILY TEMPERATURES FOR JULY

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 95 1985 66 1933* 73 1985 56 1890

2 94 1985 64 X 1910 73 1985 56 1908

3 90 1981 64 X 1912 71 1985 57 1910*

4 89 1957 65 1902 71 1981 54 X 1880

5 84 1981 66 1933 72 1981 55 1948

6 83 1981 65 1912 73 1981 57 1948*

7 86 1954 66 1909* 71 1984 56 1915

8 86 1984* 65 1902 73 1984 57 1899*

9 95 1985 66 1909* 74 1984 57 1948*

10 93 1959 67 1916* 73 1985* 57 1882

11 89 1959 66 1965* 72 1985* 58 1952*

12 85 1983 67 1909 71 1985* 55 1888

13 85 1984 66 1908 72 1984 55 1902*

14 93 1911 66 1905 73 1984 55 1902

15 90 1984 66 1899 75 1984 56 1908

16 88 2003 67 1962* 74 1984 54 X 1884

17 86 1984 66 1894 74 1984 56 1884

18 83 2004* 67 1905 74 1984 56 1884

19 87 1951 66 1916 75 1984 58 1894

20 86 2005* 67 1880 74 1984 57 1894*

21 86 1877 66 1911 73 1984* 57 1894

22 87 1960 66 1899 72 1984 59 1940*

23 89 1960 68 1932* 72 1984 58 1892

24 84 1959 67 1899* 73 1984 56 1878

25 88 1891 68 1932* 72 1931 57 1893

26 87 1977* 67 1901 74 1984 59 1932*

27 86 1972* 67 1909 74 1984 58 1892

28 92 1972 67 1905 74 1984 59 1909

29 89 1972 67 1914 73 1984 57 1893

30 100 X 1930 68 1903* 76 X 1980 56 1896

31 92 1930 67 1903 75 1980 58 1924

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
43

HIGHEST AND LOWEST DAILY TEMPERATURES FOR AUGUST

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 90 1972 67 1903 74 1980 60 1944*

2 85 1971 67 1905 72 1980 59 1944

3 85 1971 68 1909* 72 1984 57 1888

4 86 1971 68 1990* 71 1984* 59 1880

5 88 1961 68 1999* 72 1971 56 1912

6 89 1884 68 1990* 75 1982 56 1912

7 87 1983 67 1894 76 X 1983 55 1894

8 94 1936 68 1980* 75 1983 58 1944

9 89 1965 68 1932* 74 1983 60 1948*

10 85 1998* 67 1900 72 1983* 58 1894

11 86 1994 68 1907 72 1998* 58 1894

12 94 1991 68 1902 73 1984* 57 1894

13 93 1994 68 1916 76 X 1983 57 1892

14 90 1994 67 1987 74 1992* 57 1892

15 92 1884 66 X 1899 74 1992* 58 1880

16 88 1983 68 1916* 76 X 1983 59 1881*

17 88 1992* 67 1916* 75 1984 58 1932

18 90 1986 68 1912* 75 1984 59 1932*

19 88 1986 68 1902 75 1984 54 X 1884

20 89 1897 67 1924* 75 1984 58 1912

21 89 1982 69 1899 75 1984 58 1916*

22 90 1972 66 X 1924 74 1984 59 1916*

23 89 1968 69 1903* 73 1984 55 1878

24 85 1985* 67 1902* 73 1984 58 1899

25 89 1985* 66 X 1908 74 1984 57 1906

26 92 1981 68 1912 75 1981 58 1890

27 91 1915 67 1880 74 1981 58 1881

28 90 1983 67 1880 75 1984 54 X 1887

29 88 1896 67 1908* 76 X 1984 54 X 1895*

30 93 1909 67 1912* 75 1984 56 1880*

31 98 X 1955 68 1933* 73 1984 58 1942*

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
44

HIGHEST AND LOWEST DAILY TEMPERATURES FOR SEPTEMBER

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 104 1955 67 1898 73 1983 58 1881

2 99 1955 68 1999* 76 1955 56 1898*

3 92 1998* 67 1933 74 1997* 58 1916*

4 107 1988 66 1910 76 1984 55 1899

5 97 1988 66 1899 76 1984 54 1912

6 90 1952 67 1965 73 1995* 56 1942*

7 92 1949 65 1899 73 1984 55 1911*

8 100 1984 65 1933 75 1984 55 1893*

9 96 1956 67 1933* 78 X,Y 1984 54 1911

10 95 1878 67 1933 76 1984 55 1876

11 102 1959 64 X 1933 75 1984* 56 1924*

12 97 1878 64 X 1933 75 1984 54 1884*

13 92 1971* 64 X 1933 75 1984 55 1909

14 92 1879 65 1933 76 1984 53 1894*

15 100 1979 66 1933* 76 1984 52 1884

16 100 1909 66 1933 76 1984 51 1884

17 110 1913 65 1908* 78 X,Y 1984 53 1908

18 93 1939 65 1908 77 1984 50 X 1882

19 96 1939 66 1932 77 1984 50 X 1882

20 99 1939 67 1933* 76 1984* 53 1893*

21 106 1939 66 1933* 77 1939 53 1893

22 101 1939* 66 1880 77 1939 53 1944

23 103 1975 65 1933 76 1939 52 1941

24 99 1978 66 1928* 73 1982 52 1881

25 101 1978 66 1916* 74 1978 52 1920

26 111X,Y 1963 66 1908 73 1984* 50 X 1907

27 104 1963 66 1901 73 1984* 52 1908

28 99 1963 64 X 1933* 73 1963 53 1880*

29 91 1918 66 1933* 73 1984 50 X 1880

30 91 1906 64 X 1899 71 1997* 51 1880

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
45

HIGHEST AND LOWEST DAILY TEMPERATURES FOR OCTOBER

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 93 1965* 64 1903 70 1997* 52 1893

2 94 1945 63 1908 70 1997 50 1925

3 104 1987 62 1916 69 1997* 48 1884

4 97 1987 63 1912 70 1997* 48 1884

5 97 1971 64 1912 70 1997 48 1884

6 101 1971 64 1916* 70 1971 47 1884

7 91 1951 64 1939* 69 1976 48 1916

8 93 1899 64 1933 69 1983* 49 1883

9 99 1994 64 1932* 71 1983 50 1879

10 92 1991* 62 1924 70 1984 47 1879

11 89 1991* 63 1899 69 1984 46 1879

12 96 1939 65 1928* 67 1993* 47 1886

13 94 1912 62 1879 68 1991* 48 1886

14 107 X 1961 62 1899* 68 1984* 48 1892*

15 97 1961 62 1910* 73 X 1961 47 1881

16 97 1958 61 1916 68 1983* 48 1892*

17 98 1958 57 X 1895 69 1983 47 1938*

18 91 1940 63 1916* 69 1976 47 1881

19 97 1964 62 1920 68 1983 46 1892*

20 95 1964 62 1916 70 1976 46 1949

21 101 1965 63 1924* 68 1978* 45 1949*

22 104 1965 63 1916 68 1965* 46 1906

23 93 1965 62 1941 67 1982 47 1886

24 94 1965* 63 2000* 69 1982 47 1892

25 95 1983 61 1924* 67 1982 48 1879

26 92 1983* 63 1924* 71 1983 46 1874

27 91 1879 61 1883 71 1983 47 1885

28 92 1879 62 1946* 69 1983 47 1874

29 89 1931 61 1971 69 1983 45 1971

30 89 1962 61 1920* 68 1983 43 X 1971

31 90 1918 60 1886 67 1983 45 1894

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 
46

HIGHEST AND LOWEST DAILY TEMPERATURES FOR NOVEMBER

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 97 X 1966 61 1916* 68 X 1983 45 1916*

2 90 1997* 61 1935 63 1983 44 1886

3 93 1921 61 1916 65 1888 47 1876

4 97 X 1976 62 1924* 63 1983* 44 1935*

5 92 1976 59 1905 68 X 1983 42 1881

6 90 1949 59 1905 64 1983 46 1935*

7 89 1956 60 1890 62 1997* 46 1874

8 93 1904 62 1946* 64 1983 46 1881*

9 96 1956 59 1879 63 2002* 42 1881

10 91 1956 59 1912 62 2003* 44 1919

11 86 1974* 59 1909 63 1980 43 1915*

12 91 1974 60 1938* 68 X 1983 42 1938

13 89 1949 59 1910 66 1983 40 1880

14 87 1949 59 1964* 61 1983* 39 1916

15 89 1940 58 1894 60 1875 38 1964

16 86 1912 59 1958 62 1966 42 1958

17 88 1976 57 1964 64 1986 41 1958

18 86 1949 55 1893 62 1983* 38 1881

19 85 1917* 59 1994* 62 1967 39 1994

20 86 1914 59 1898 62 1967 38 1964

21 86 1954 56 1905 62 1936 40 1941

22 86 1939 57 1906 61 1976 40 1931

23 86 1950* 56 1906 61 1965 38 1931

24 87 1932 56 1909* 60 1981* 38 1931*

25 89 1953 58 1908 61 1989 39 1906

26 85 1956 58 1906 64 1976 41 1880

27 83 1903 54 X 1919 61 1903 40 1948*

28 82 1980 56 1919 59 1977* 36 X 1919

29 86 1907 54 X 1906 60 1982 41 1919*

30 85 1964 56 1908* 59 1892* 40 1931*

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR 

 
47

HIGHEST AND LOWEST DAILY TEMPERATURES FOR DECEMBER

MAXIMUM TEMPERATURES MINIMUM TEMPERATURES

DAY HIGH YEAR LOW YEAR HIGH YEAR LOW YEAR

1 83 1959 59 1933* 60 1983* 38 1884

2 83 1959 58 1909* 59 1925 42 1991

3 85 1958 57 1909* 59 1969* 42 1909*

4 83 1979 57 1908 60 1980 39 1909

5 83 1965 54 1909 60 1966 38 1948

6 85 1979 58 1998 59 1995 40 1891

7 80 1989* 57 1909 58 2000 37 1891

8 84 1938 51 1884 62 1988 34 1978

9 84 1957 55 1972 60 1977 35 1960

10 84 1950 54 1972 60 1991 40 1884

11 84 1958 53 1927 61 1977* 39 1947

12 81 1952 56 1932* 59 1934 36 1949

13 81 1952 55 1901 59 1922 35 1901

14 83 1953 55 1987* 59 1889 36 1878

15 81 1958 54 1967 60 1977 35 1878

16 84 1980 55 1948* 62 1957* 38 1892*

17 82 1979 54 1924 57 1962* 38 1916

18 83 2004 55 1897 58 1977* 36 1892*

19 80 1954 54 1916 59 1921 36 1909

20 82 1954 55 1990 59 1969 37 1878

21 80 2005* 53 1990 59 1969* 37 1968*

22 80 1899 52 1990 61 1977 36 1968*

23 78 1989* 53 1879 61 1977 36 1990

24 79 1989 52 1879 59 1977* 36 1879

25 83 1925 52 1916 63 1977 32 X 1879

26 79 1919* 51 1916 62 1977 32 X 1891

27 85 1956 54 1916 64 1977 37 1987*

28 84 1919 54 1916 63 1977 37 1987

29 88 X 1963 54 1879 62 1977 38 1966*

30 87 1980 49 X 1915 61 1977 34 1895

31 80 1958 53 1905 65 X 1977 35 1918

* - LAST OF SEVERAL OCCURRENCES 

X - RECORD FOR THE MONTH Y - RECORD FOR THE YEAR
48

PRESSURE STATISTICS

Two Highest Monthly Sea Level Pressures in 

inches

Average 

Station 

Pressure

Two Lowest Monthly Sea Level Pressures in 

inches

January 30.48 1913 1017.0 mb January 29.46 1988

 30.47 1916 30.03 in 29.48 1882

February 30.53 1883 1017.0 mb February 29.48 1913

 30.49 1916 30.03 in 29.50 1980

March 30.45 1917, 1971 1015.2 mb March 29.37 1983

 30.41 1890 29.98 in 29.46 1912

April 30.36 1875 1015.0 mb April 29.61 1941

 30.33 1945 29.97 mb 29.67 1886, 1932, 1998

May 30.26 1879 1013.3 mb May 29.67 1902

 30.22 1983 29.92 in 29.68 1876, 1923, 1937

June 30.17 1953, 1998 1012.3 mb June 29.65 1976

 30.12 1873,1971, 1975 29.89 in 29.66 1904

July 30.17 1980 1012.5 mb July 29.66 1936

 30.13 1974 29.90 in 29.68 1934

August 30.16 1896 1012.3 mb August 29.64 1906,1933, 1981

 30.10 29.89 in 29.66 1995

September 30.16 1972 1011.5 mb September 29.53 1927

 30.14 1889 29.87 in 29.59 1896, 1930, 1963, 

October 30.27 1957 1013.9 mb October 29.57 1887, 1928

 30.24 1886 29.94 in 29.60 1925,1959

November 30.41 1975 1015.8 mb November 29.52 1919

 30.40 1979 30.00 in 29.60 1931

December 30.53 1978 1017.2 mb December 29.49 1959

 30.47 1997 30.04 in 29.51 1940

Extreme Highest Yearly Average Extreme Lowest

30.53 in February 1883 and 

 December 1978 

1014.4 mb 

29.955 in 

29.37 in March 1983 
49
50
51
52
53

TOTAL SEASONAL RAINFALL

05

1015202530

1850-51 1855-56 1860-61 1865-66 1870-71 1875-76 1880-81 1885-86 1890-91 1895-96 1900-01 1905-06 1910-11 1915-16 1920-21 1925-26 1930-31 1935-36 1940-41 1945-46 1950-51 1955-56 1960-61 1965-66 1970-71 1975-76 1980-81 198

Water Year

Total Seasonal Precipitation (inches)

Seasonal Rainfall 30 Year Moving Average
54

MONTHLY AND SEASONAL PRECIPITATION (in inches)

Year July August Sept Oct Nov Dec Jan Feb March April 

1850-51 0 0 0 0.19 2.82 1.93 0.03 1.51 0.34 0.87 1851-52 0 0 0.02 0.01 0.25 3.74 0.58 1.84 1.87 0.85 1852-53 0 0.4 0 0.06 1.45 4.5 0.5 0.2 1.52 0.25 1853-54 0 0.21 0 0 1.28 1.77 0.99 2.56 1.88 0.89 1854-55 0.07 1.36 0.09 0.27 0.04 3.29 1.97 3.59 1.3 1.52 1855-56 0 0.04 0 0.11 2.15 0.41 1.27 1.86 1.59 2.17 1856-57 0 0 0.07 0 1.22 1.3 0.26 1.76 0 0.04 1857-58 0 0.02 0.01 0.49 2.16 1.3 1.52 0.44 1.24 0.17 1858-59 0 0.04 0.1 0.47 0.28 3.1 0 1.89 0.2 0.36 1859-60 0.02 0 0 0.18 1.49 1.79 0.72 1.49 0.15 0.65 1860-61 0.14 0 0 0 2.88 2.99 0.82 0.79 0.05 0.04 1861-62 0 0 1.59 0.05 1.19 3.2 5.56 1.39 0.97 1.05 1862-63 0.11 0 0 0.89 0.05 0.93 0.32 1.09 0.33 0.13 1863-64 0 0 0.36 0 0.73 0.04 0.04 2.5 0.2 0.01 1864-65 0.11 0 0 0.04 2.41 1.04 1.28 3 0 0.56 1865-66 1.29 0 0 0.02 0.52 0.84 5.05 3.43 1.47 0.11 1866-67 0 0.1 0 0 0.24 1.82 2.32 0.85 7.88 0.48 1867-68 0 0.3 0 0.34 0.45 3.06 3.37 1.63 0.73 1.2 1868-69 0.51 0 0.05 0 2 1.52 2.88 1.88 1.98 0.53 1869-70 0.05 0 0 0.05 2.32 0.94 0.54 0.77 0.33 0.2 1870-71 0.04 0.07 0 1.54 0.18 0.42 0.52 1.35 0.01 0.7 1871-72 0 0 0 0 1.33 1.39 0.99 1.63 0.46 0.26 1872-73 0 0.18 0 0 0 1.43 0.44 4.21 0.11 0.1 1873-74 0 1.95 0 0 0.77 5.46 3.11 3.73 1.2 0.34 1874-75 0.12 0 0.13 0.53 0.88 0.55 2.38 0.37 0.45 0.12 1875-76 0 0.21 0.39 0 2.25 0.41 2.47 2.44 1.78 0.06 

T indicates a trace - unmeasurable
55

MONTHLY AND SEASONAL PRECIPITATION (in inches)

Year July August Sept Oct Nov Dec Jan Feb March April 

1876-77 0.03 0.06 0.03 0.08 0.04 0.15 1.05 0.18 1.44 0.26 1877-78 0 0 T 0.81 0.06 3.89 1.45 4.83 1.41 2.91 1878-79 0 T 0 0.96 T 1.57 3.54 1.04 0.1 0.6 1879-80 0 0 0 0.29 2.77 6.32 0.61 1.5 1.43 1.34 1880-81 0.09 0.32 0 0.53 0.28 4.15 0.52 0.45 1.88 1.35 1881-82 0 0.01 0.04 0.24 0.12 0.3 4.53 2.55 1.02 0.45 1882-83 0 T 0.01 0.41 0.39 0.13 1.09 0.95 0.41 0.31 1883-84 0 0 0 2.01 0.2 1.82 1.34 9.05 6.23 2.84 1884-85 0 T 0.07 0.35 0.11 5.12 0.35 0.02 0.78 1.2 1885-86 T 0.13 T 0.31 1.56 0.71 6.95 1.51 3.73 1.95 1886-87 T T 0 0.05 0.95 0.1 0.04 4.51 0.02 2.14 1887-88 0.01 T T T 2.08 1.14 1.96 1.48 2.79 0.1 1888-89 0.01 T 0.04 0.26 1.83 2.84 1.72 1.8 2.2 0.19 1889-90 T 0.04 T 2.12 0.12 7.71 2.79 1.7 0.41 0.05 1890-91 0 T 0.65 0.01 0.72 1.61 1.21 4.84 0.27 0.76 1891-92 T 0 0.08 0.04 0.1 1.29 1.58 2.96 0.96 0.41 1892-93 0 0.05 T 0.22 0.94 0.69 0.78 0.47 5.5 0.22 1893-94 T 0 0 0.11 0.91 1.91 0.29 0.49 1.05 0.11 1894-95 0 0.04 0.01 T 0 2.26 7.33 0.53 1.43 0.11 1895-96 0 0 0.01 0.27 1.19 0.27 1.27 0.02 2.89 0.25 1896-97 T 0.13 T 0.97 0.98 2.18 3.13 2.72 1.53 0.02 1897-98 0.01 T T 1.06 0.02 0.32 1.71 0.06 0.91 0.22 1898-99 0 0 0.07 0 0.15 0.87 2.34 0.3 0.85 0.29 

1899-1900 0 0.07 0 0.35 0.86 0.65 0.69 0.03 0.53 1.26 

1900-01 0 T T 0.3 1.43 0 2.08 4.77 1.07 0.01 1901-02 T T 0.06 0.28 0.41 0.02 1.7 1.57 1.86 0.21 1902-03 0.92 T T 0.06 1.53 3.58 0.69 2.27 1.17 1.4 

T indicates a trace - unmeasurable
56

MONTHLY AND SEASONAL PRECIPITATION (in inches)

Year July August Sept Oct Nov Dec Jan Feb March April 

1903-04 0 T T 0.07 T 0.35 0.04 1.5 2.17 0.15 1904-05 0 T T 0.17 0 2.46 2.16 5.9 2.98 0.3 1905-06 0.16 0 0.5 0.25 3.38 0.38 0.98 2.62 4.68 0.98 1906-07 T 0.1 0.12 0.03 0.62 4.02 3.27 0.45 1.62 0.13 1907-08 0.03 0 0 1.71 0.05 0.43 2.8 2.41 0.61 0.35 1908-09 0 0.64 0.2 0.15 1 0.27 3.57 1.76 2.62 0.02 1909-10 T T 0.02 0 2.39 3.76 2 0.19 1.3 0.08 1910-11 0.01 0.05 0.17 1.35 0.4 0.15 3.35 4.92 0.92 0.65 1911-12 0.12 0 0.1 0.28 0.02 1.39 0.66 0 5.72 2.13 1912-13 0.14 0.26 0 0.89 0.4 0.03 1.19 2.4 0.42 0.08 1913-14 0.06 0.02 0.02 T 2.23 0.72 3.59 1.9 0.36 0.85 1914-15 0 0 T 1.05 0.86 2.21 4.91 3.62 0.33 1.15 1915-16 T 0 T 0 0.73 2.6 7.56 0.66 0.98 0.01 1916-17 0.02 0.01 0.25 0.87 0.05 1.14 4.32 1.84 0.26 1.06 1917-18 T T T 0.17 0.08 T 1.64 1.52 4.57 T 1918-19 T 0.11 0.08 0.42 1.91 1.68 0.61 1.46 1.83 0.3 1919-20 T 0.01 0.26 1.04 0.43 0.48 0.43 2.87 2.46 0.47 1920-21 T 0.01 0.08 0.18 0.19 0.54 2.02 0.35 1.13 0.04 1921-22 T T 1.24 0.67 0.3 9.26 3.45 1.86 1.34 0.17 1922-23 0.01 T 0 0.09 0.75 1.21 1.34 1.53 0.34 1.05 1923-24 0.01 T 0.03 0.37 0.16 1.65 0.26 T 2.41 0.77 1924-25 0 T 0 0.35 0.55 1.34 0.08 0.3 1.78 1.11 1925-26 T 0.01 0 3.67 1.16 1.5 0.78 2.33 0.82 5.37 1926-27 T 0.05 0 0.21 0.59 3.89 0.32 6.68 2.05 0.71 1927-28 0 0.01 0.04 1.76 0.05 4.57 0.21 0.79 0.69 0.14 1928-29 T 0.03 T 0.14 0.63 2.42 0.9 1.14 1.22 0.57 1929-30 0 0 0.26 0 T 0 3.9 0.66 3.02 1.06 1930-31 T T T 0.22 1.04 0 3.72 4.11 0.06 1.38 

T indicates a trace - unmeasurable
57

MONTHLY AND SEASONAL PRECIPITATION (in inches)

Year July August Sept Oct Nov Dec Jan Feb March April 

1931-32 T 0.08 T 0.05 1.95 3.56 1.45 5.15 0.42 0.5 1932-33 T 0 0 1.1 0.3 2.4 4.32 0.02 0.13 1.75 1933-34 0.02 0.01 0.02 0.16 0.03 1.1 0.3 1.88 0.24 0.01 1934-35 T 0.02 0.18 0.42 1.95 3.38 2.15 4.54 1.42 1.02 1935-36 T 0.18 0.01 0.05 0.07 0.74 0.75 5.18 0.92 0.48 1936-37 0.01 0.28 0.04 1.86 0.44 4.45 1.52 4.22 2.65 0.13 1937-38 0.16 0 T T 0.02 1.06 0.89 3.26 3.73 0.44 1938-39 T 0.03 0 0.23 0.02 4.25 2.38 1.23 1.17 0.47 1939-40 T T 2.58 0.61 1.04 0.48 1.75 3.56 0.82 0.46 1940-41 T T 0.08 1.5 0.49 6.09 2.03 5.31 5.89 3.35 1941-42 0.06 0.03 0.28 2.9 2.23 2.85 0.21 1.06 1.91 1.4 1942-43 0 T 0 0.27 0.27 0.69 6.26 1.4 1.66 0.52 1943-44 0 T 0.04 0.2 0.03 7.6 1.22 3.65 0.8 0.61 1944-45 T T T T 4.93 1.53 0.42 1.91 2.03 0.03 1945-46 T 0.87 0.03 T 0.13 3.62 0.89 0.6 2.67 0.52 1946-47 0 T T 0.34 2.53 1.18 0.35 0.43 0.97 0.36 1947-48 0 0 0.18 0.08 0.72 3.02 T 1.07 1.6 0.13 1948-49 T 0 T 1.32 0.1 2.38 3.56 1.81 0.75 0.09 1949-50 T T T 0.23 1.16 0.86 3.31 1.62 1 0.28 1950-51 0.08 0 T 0.01 1.23 0.05 1.6 0.5 0.5 1.95 1951-52 0 0.85 0.04 0.68 1.23 3.87 4.24 0.6 4.97 1.54 1952-53 T T T T 1.83 2.2 0.58 0.58 0.79 0.33 1953-54 T T T 0.07 0.8 0.03 2.76 1.03 4.31 0.09 1954-55 T T 0 0 0.74 0.55 3.59 0.56 0.38 0.9 1955-56 T 0.11 T T 0.55 0.33 1.65 0.22 T 1.56 1956-57 T T T 0.68 0 0.18 4.8 0.5 0.75 0.84 1957-58 T T 0.37 1.76 0.59 1.38 0.62 3.15 3.98 1.65 

T indicates a trace - unmeasurable
58

MONTHLY AND SEASONAL PRECIPITATION (in inches)

Year July August Sept Oct Nov Dec Jan Feb March April 

1958-59 T T 0.62 0.01 0.44 0.06 0.08 3.76 T 0.31 1959-60 T T 0.04 0.23 0.02 1.44 2.99 1.45 0.55 0.56 1960-61 T 0 0.06 0.04 1.01 0.22 1.21 0.06 0.85 T 1961-62 T 0.04 T 0.2 0.79 1.45 2.71 3.08 0.64 0.01 1962-63 T T 0 0.01 0.01 0.22 0.11 1.22 1.33 0.71 1963-64 0 T 1.9 0.13 1.85 0.1 1.3 0.37 0.97 0.2 1964-65 0 T 0 0.02 1.01 1.17 0.4 0.52 1.79 3.58 1965-66 0.02 T 0.29 T 5.82 6.6 1.29 0.86 0.17 T 1966-67 T 0 T 0.8 0.82 3.22 2.2 0 1.14 2.24 1967-68 0.01 0.14 0.08 0 3.53 1.66 0.35 0.22 1.55 0.34 1968-69 0.13 T T 0.04 0.36 0.61 4.78 4.34 0.94 0.21 1969-70 T 0.01 T 0.04 0.79 0.46 0.86 2.58 1.5 0.09 1970-71 T 0 T 0.07 2.05 2.22 0.3 1.27 0.2 0.93 1971-72 T 0.03 T 1.66 0.06 3.27 0.07 0.1 T 0.02 1972-73 T 0.02 0.44 0.58 3.16 1.61 1.68 1.63 2.26 0.05 1973-74 T T 0.02 0.01 1.63 0.19 2.96 0.04 1.7 0.02 1974-75 0.01 T T 1.03 0.14 2.2 0.49 0.96 3.79 2 1975-76 T T T 0.09 0.64 0.37 T 5.4 0.99 1.33 1976-77 0.02 0.01 1 0.38 0.75 1.06 2.36 0.06 0.61 0.01 1977-78 T 2.13 T 0.5 0.05 1.67 5.95 2.64 5 0.73 1978-79 0 T 0.72 0.05 2.09 2.19 5.82 0.85 3.71 0.02 1979-80 0.09 0.01 0 0.73 0.27 0.02 5.58 4.47 2.71 1.18 1980-81 T 0 T 0.05 0 0.31 1.48 2.26 3.74 0.22 1981-82 T 0 0.03 0.14 1.79 0.54 2.71 0.88 4.74 0.62 1982-83 0 T 0.38 0.05 2.1 1.43 2.1 3.88 6.57 1.74 1983-84 0.01 0.39 0.21 0.4 1.94 1.53 0.46 0.09 0.04 0.62 1984-84 0.19 0.06 T 0.29 2.37 4.55 0.52 0.77 0.58 0.32 

T indicates a trace - unmeasurable
59

MONTHLY AND SEASONAL PRECIPITATION (in inches)

Year July August Sept Oct Nov Dec Jan Feb March April 

1985-86 0 T 0.2 0.29 4.92 1.06 0.75 2.59 3.12 1.17 1986-87 T 0 1.04 1.39 1.16 0.95 1.68 1.53 1.04 0.78 1987-88 0.03 0.01 0.7 1.74 1.33 2.73 0.89 1.37 0.59 3.71 1988-89 T T T T 1.39 2.23 0.42 0.7 0.69 0.12 1989-90 0 T 0.23 0.47 0.09 1.01 2.52 1.13 0.25 0.76 1990-91 T 0.01 T T 0.65 0.59 1.06 2.46 6.96 0.05 1991-92 0.24 0.01 0.28 0.69 0.05 1.7 1.81 3.34 4.42 0.28 1992-93 0.03 0.05 0 0.18 0.03 2.56 9.09 4.73 1.22 0 1993-94 0.03 T T 0.22 0.77 0.78 0.7 2.75 3.67 0.93 1994-95 0.03 0.01 T 0.01 0.46 0.8 8.06 1.93 3.81 0.96 1995-96 0.05 0 T T 0.3 0.88 1.52 0.88 1.1 0.36 1996-97 0.09 T 0.03 0.94 1.70 0.64 3.02 0.31 0 0.28 1997-98 T 0 0.85 0.02 1.17 1.35 2.68 7.65 2.21 1.11 1998-99 0.20 T 0.03 0.08 0.69 0.67 1.54 0.70 1.09 1.62 1999-00 T 0 0.02 0 0.04 0.32 0.18 3.68 1.00 0.54 2000-01 0 0.01 T 1.24 0.26 0.01 3.30 2.38 0.63 0.76 2001-02 T 0 0 0 0.99 0.45 0.32 0.17 0.46 0.63 2002-03 0 T 0.31 0.04 0.32 1.98 0.02 4.88 1.36 1.41 2003-04 T 0 0 T .60 .61 .34 2.81 .22 .60 2004-05 0 0 T 4.98 .33 4.01 4.49 5.83 2.12 .59 2005-06 .01 T .10 .46 .12 .25 

 Averages 0.04 0.09 0.13 0.41 0.98 1.81 1.96 1.91 1.66 0.71 

T indicates a trace - unmeasurable
* last of several occurrences 

60

GREATEST DAILY PRECIPITATION

JANUARY FEBRUARY MARCH APRIL 

DAY HIGHEST YEAR HIGHEST YEAR HIGHEST YEAR HIGHEST YEAR

1st .70 1910 .99 1880 1.64 1981 .77 1958

2nd 1.53 1879 1.64 1905 1.95 1992 .51 1880

3rd .62 1917 1.52 1998* 1.32 1896 .55 1965

4th 2.24 1995 1.13 1935 1.12 2005 .75 1926

5th .99 1992 1.13 1935 1.18 1981 3.23 1926

6th 1.19 1993 2.71 1937 1.44 1975 1.13 1986

7th 1.27 1957 .78 1983 2.11 1952 .57 1965

8th .96 1931 1.71 1976 1.33 1968 1.21 1965

9th 1.02 1980 2.39 1901 .79 1884 .82 1912

10th 1.76 1911 1.21 1915 .98 1980 1.03 1952

11th 1.56 1886 1.19 2005 1.77 1995* 1.18 1941

12th 2.49 1882 1.20 2003 1.10 1941 .83 1956

13th 1.29 1952 1.01 1878 1.28 1941 .28 1886

14th 2.12 1978 1.84 1927 1.39 1942* 1.06 2003

15th 1.80 1993 1.96 1887 1.40 1930 .82 1878

16th 1.12 1993 1.67 1932 1.32 1958 .86 1917

17th 1.55 1916 1.38 1998 2.03 1982 .61 1903

18th 1.35 1874 .81 1980 .57 1886 .42 1983

19th 2.15 1895 1.47 1993 1.15 1991 .70 1881

20th 1.37 1962 1.41 1980 .98 1919 1.42 1988

21st 1.67 1915 2.18 2005 1.83 1893 1.33 1988

22nd 1.53 1967 1.50 1941 1.39 1954 .46 1914

23rd 2.23 1943 1.09 1891 .81 1904 .25 1980

24th .62 1941 1.17 1873 2.36 1906 .28 1967

25th 1.99 1995 1.48 2003 .85 1998 .86 1951

26th 2.04 1914 1.14 1902 .98 1991 1.06 1931

27th 2.19 1916 1.61 1911 .92 1991 .80 1885

28th 1.32 1915 1.64 1970 .99 1896 1.34 1933

29th 1.92 1980 .75 1888 .47 1925 .46 1983

30th .80 1966 1.00 1946 .88 1930

31st 2.57 1979 1.18 1941 
* last of several occurrences 

61

GREATEST DAILY PRECIPITATION

MAY JUNE JULY AUGUST 

DAY HIGHEST YEAR HIGHEST YEAR HIGHEST YEAR HIGHEST YEAR

1st .54 1980 .25 1899 .03 1994 .01 1991*

2nd .23 1905 .05 1944* .05 1902 .03 1971

3rd .95 1892 .13 1952 .02 1912 T 1955*

4th .85 1900 .12 1945 T 1980* .02 1961

5th 1.01 1921 .38 1993 .01 1986 .05 1926

6th .31 1921 .29 1934 .03 1968 .02 1983

7th .32 1971 .07 1879 .02 1992 .15 1983

8th 1.49 1977 .07 1998 .08 1950 .25 1936

9th .22 1893 .38 1990 T 1959* .64 1908

10th .38 1933 .49 1990 .09 1996 .03 1945*

11th .42 1957 .26 1963 .02 1880 .15 1873

12th .69 1883 .14 1967 T 1958* 1.80 1873

13th .28 1955 .15 1884 T 1990* .05 1992

14th .40 1884 .05 1878 .16 1905 .17 1983

15th 1.05 1884 .13 1995 .07 1880 .07 1918

16th .07 1921 .17 1995 .05 1995 1.44 1977

17th .29 1883 .14 1995 .12 1912 .69 1977

18th .17 1922 .08 1953 .01 1922* .83 1945

19th .44 1887 .02 1928* T 1994* .01 1933

20th .25 1878 .28 1972 .20 1998 .08 1906

21st .58 1921 .01 1982 .02 1911 T 1975*

22nd .36 1921 .04 1992 .09 1874 T 1924

23rd .17 1882 .01 1918 .01 2005 T 1959*

24th .07 1917 .03 1918 T 1990* .13 1885

25th .19 1931 .03 1913 .83 1902 .18 1935

26th .10 1942 .01 1952* .05 1941 .01 1994*

27th .10 1962 .02 1913 .13 1984 .04 1894

28th .49 1990 .06 1925 .10 1968 .76 1951

29th .20 1877 .16 1912 .14 1937 .11 1912

30th .09 1884 T 1972* .01 1923 .21 1875

31st .11 1925 .23 1991 .14 1967
* last of several occurrences 

62

GREATEST DAILY PRECIPITATION

SEPTEMBER OCTOBER NOVEMBER DECEMBER

DAY HIGHEST YEAR HIGHEST YEAR HIGHEST YEAR HIGHEST YEAR

1st .02 1909 .44 1921 .31 2003 .94 1889

2nd T 1950* .23 1916 .44 1875 1.06 1925

3rd .07 1884 .55 1914 .14 1960 1.03 1928

4th .86 1963 2.95 1925 .28 1957 2.52 1873

5th .44 1939 .55 1925 1.69 1905 1.34 1966

6th .65 1939 .35 1912 .62 1905 .73 1966

7th .37 1957 .57 1939 .77 1931 1.15 1992

8th .16 1982 .24 1889 .52 1946 1.66 1884*

9th .09 1976 .74 1932 2.68 1879 1.53 1926

10th .87 1976 .91 1986 .96 1949 2.56 1943

11th .02 1939* .51 1987 1.96 1944 1.22 1943

12th .30 1939 .45 1941 1.71 1941 1.01 1943

13th .28 1941 1.54 1889 1.11 1950 .85 1902

14th .29 1875 .78 1887 1.12 1944 1.18 1889

15th .12 1906 .96 1878 1.07 1965 2.35 1938

16th .07 1965 .68 1971 1.25 1965 1.36 1987

17th .48 1963 .72 1971 1.08 1986 1.76 1902

18th .41 1963 1.00 1948 .58 1973 1.93 1921

19th .19 1939 .58 2004 .70 1913 .75 1970

20th .24 1991 .95 2004 1.46 1963 2.09 1921

21st .07 1947 .32 1976 1.22 1967 1.07 1921

22nd .70 1987 .91 1941 1.53 1965 2.60 1945

23rd .14 1958 .88 1941 1.75 1887 2.31 1940

24th .48 1958 1.00 1919 .62 1984 1.47 1940

25th .90 1986 .80 1940 2.04 1985 1.50 1921

26th .13 1919 .44 1991 .95 1909 1.90 1921

27th .15 1890 2.70 2004 .75 1939 2.15 1879

28th .16 1905 .60 1974* 1.32 1981 1.27 2004

29th .37 1890 .50 2000 .92 1970 1.61 2004

30th 1.23 1921 .68 1957 .33 1982 1.96 1951

31st 1.01 1927 .81 1904
63

* last of several occurrences 

NUMBER OF CONSECUTIVE DAYS WITH NO MEASURABLE PRECIPITATION

Days Year Time Period # of Traces

182 2004 April 17 to October 16 2 

181 2003 May 3 to October 31 14 

165 1988 May 30 to November 10 11 

164 1915 May 25 to November 4 4 

164 1924 April 25 to October 5 5 

164 1997 April 4 to September 14 3 

161 1893 May 14 to October 21 2 

159 2001 May 29 to November 3 2 

153 1914 May 2 to October 1 10 

152 1949 May 20 to October 18 15 

149 1954 June 14 to November 9 12 

148 1956 May 28 to October 22 9 

147 1944 June 11 to November 4 13 

145 1966 May 12 to October 3 9 

139 1917 May 30 to October 15 12 

138 1959 April 27 to September 11 5 

136 1877 May 30 to October 12 2 

135 1909 April 19 to August 31 6 

133 1952 June 27 to November 6 12 

131 1904 May 27 to October 4 3 

128 1903 May 26 to September 30 4 

128 1940 April 28 to September 2 12 

128 1970 May 28 to October 2 12 

127 1946 May 27 to September 30 3 

YEARS THAT MEASURABLE PRECIPITATION FELL EVERY MONTH

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1854 .99 2.56 1.88 .89 .18 .01 .07 1.36 .09 .27 .04 3.29 11.63 

1876 2.47 2.44 1.78 .06 .05 .05 .03 .06 .03 .08 .04 .15 7.24 

1933 4.32 .02 .13 1.75 .53 .08 .02 .01 .02 .16 .03 1.10 8.17 
64

MAXIMUM MONTHLY PRECIPITATION WITH FOUR INCHES OR MORE

Amount Date Amount Date Amount Date

9.26 December 1921 5.58 January 1980 4.73 February 1993 

9.09 January 1993 5.56 January 1862 4.68 March 1906 

9.05 February 1884 5.50 March 1893 4.57 December 1927 

8.06 January 1995 5.46 December 1873 4.57 March 1918 

7.88 March 1867 5.40 February 1976 4.55 December 1984 

7.65 February 1998 5.37 April 1926 4.54 February 1935 

7.71 December 1889 5.31 February 1941 4.53 January 1882 

7.60 December 1943 5.18 February 1936 4.51 February 1887 

7.56 January 1916 5.15 February 1932 4.50 December 1852 

7.33 January 1895 5.12 December 1884 4.49 January 2005 

6.96 March 1991 5.05 January 1866 4.47 February 1980 

6.95 January 1886 5.00 March 1978 4.45 December 1936 

6.68 February 1927 4.98 October 2004 4.42 March 1992 

6.60 December 1965 4.97 March 1952 4.34 February 1969 

6.57 March 1983 4.93 November 1944 4.32 January 1933 

6.32 December 1879 4.92 November 1985 4.32 January 1917 

6.26 January 1943 4.92 February 1911 4.31 March 1954 

6.23 March 1884 4.91 January 1915 4.25 December 1938 

6.09 December 1940 4.88 February 2003 4.24 January 1952 

5.95 January 1978 4.84 February 1891 4.22 February 1937 

5.90 February 1905 4.83 February 1878 4.21 February 1873 

5.89 March 1941 4.80 January 1957 4.15 December 1880 

5.83 February 2005 4.78 January 1969 4.11 February 1931 

5.82 January 1979 4.77 February 1901 4.02 December 1906 

5.82 November 1965 4.74 March 1982 4.01 December 2004 

5.72 March 1912 
65

GREATEST RAINFALL FOR A CALENDAR DAY

Amount Date Amount Date Amount Date 

3.23 April 5, 1926 2.11 March 7, 1952 1.73 February 15, 1927 

2.95 October 4, 1925 2.09 December 20, 1921 1.71 February 8, 1976 

November 12, 1941 

2.71 February 6, 1937 2.04 January 26, 1914 

November 25, 1985 

 

2.70 October 27, 2004 2.03 February 17, 1982 

2.68 November 9, 1879 2.01 January 14, 1969 

2.60 December 22, 1945 1.99 January 25, 1995 

2.57 January 31, 1979 1.96 February 15, 1887 

November 11, 1944 

December 30, 1951 

 

2.56 December 10, 1943 1.95 March 2, 1992 

2.52 December 4, 1873 1.93 December 18, 1921 

2.49 January 12, 1882 1.92 January 29, 1980 

2.39 February 9, 1901 1.90 December 26, 1921 

2.36 March 24, 1906 1.85 January 29, 1950 

2.35 December 15, 1938 1.84 February 14, 1927 

2.31 December 23, 1940 1.83 March 21, 1893 

2.24 January 4, 1995 1.82 October 27, 1883 

2.23 January 23, 1943 1.80 August 12, 1873 

January15, 1993 

 

2.19 January 27, 1916 1.79 December 20, 1879 

2.18 February 21, 2005 1.77 March 11, 1918 March 

11, 1995 

 

2.15 January 19, 1895 

December 27, 1879 

December 10, 1965 

1.76 January 10, 1911 

February 6, 1935 

December 17, 1902 

 

2.12 January 14, 1978 1.75 January 15, 1895 

November 23, 1887 

December 15, 1889 

 
66

PRECIPITATION STATISTICS BY THE MONTH (in inches)

January February March April May June

Greatest Daily Precipitation 2.57 on the 

31st in 

1979 

2.71 on the 

6th in 1937 

2.36 on the 

24th in 

1906 

3.23 on the 

5th in 1926 

1.49 on the 

8th in 1977 

.49 on the 

10th in 

1990 

Normal for the Month 

(1971-2000)

2.28 2.04 2.26 .75 .20 .09 

Maximum Monthly Precipitation 9.09 in 

1993 

9.05 in 

1884 

7.88 in 

1867 

5.37 in 

1926 

2.54 in 

1921 

.87 in 1990 

Minimum Monthly Precipitation 0 in 1850 

and 1859 

0 in 1912 

and 1967 

0 in 1865, 

1857, and 

1997 

T in 1918, 

1961, and 

1966 

0 in 1952 

and 1984 

0 in 2004* 

Normal Seasonal1 through 

the Month

5.55 7.08 8.85 9.64 9.83 9.90 

Maximum Seasonal1 through the 

Month

15.15 in 

2004-05 

19.64 in 

2004-05 

21.76 in 

2004-05 

24.74 in 

1940-41 

25.66 in 

1883-84 

25.97 in 

1883-84 

Minimum Seasonal1 through the 

Month

0.35 in 

1962-63 

1.57 in 

1962-63 

2.39 in 

2001-02 

3.02 in 

2001-02 

3.02 in 

2001-02 

3.02 in 

2001-02 

Greatest in 5 minutes 

(through 1991) 

.26 on the 

5th in 1935 

.27 on the 

14th in 

1981* 

.33 on the 

1st in 

1983* 

.28 on the 

8th in 1926 

.19 on the 

4th in 1930 

.09 on the 

6th in 1934 

Greatest in 10 minutes 

(through 1991) 

.36 on the 

5th in 1935 

.49 on the 

14th in 

1927 

.48 on the 

9th in 1926 

.35 on the 

5th in 1926 

.21 on the 

8th in 

1977* 

.16 on the 

6th in 1934 

Greatest in 15 minutes 

(through 1991) 

.49 on the 

10th in 

1955 

.63 on the 

14th in 

1927 

.59 on the 

9th in 1926 

.47 on the 

5th in 1926 

.25 on the 

8th in 1977 

.17 on the 

6th in 1934 

Greatest in 30 minutes 

(through 1991) 

.68 on the 

10th in 

1955 

.76 on the 

14th in 

1927 

.94 on the 

15th in 

1905 

.75 on the 

5th in 1926 

.33 on the 

8th in 1977 

.17 on the 

6th in 1934 

Greatest in 60 minutes 

(through 1991) 

.87 on the 

19th in 

1933 

1.12 on the 

28th in 

1970 

1.21 on the 

7th in 1952 

1.16 on the 

5th in 1926 

.46 on the 

8th in 1977 

.19 on the 

6th in 

1934 

Greatest in 2 hours 

(through 1991) 

1.06 on the 

10th in 

1096 

1.50 on the 

28th in 

1970 

1.64 on the 

7th in 1952 

2.09 on the 

5th in 1926 

.62 on the 

8th in 1977 

.39 on the 

10th in 

1990 

Greatest in 24 hours 2.65 on the 

14-15 in 

1978* 

2.90 on the 

6-7 in 1937 

2.40 on 7-8 

in 1952 and 

24-25 in 

1906 

3.23 on the 

5th in 1926 

1.50 on 

 8-9 in 1977 

.38 on 5-6 

in 1934 

* Last of Several Occurrences 

1

 The season begins on July 1st 
67

 

PRECIPITATION STATISTICS BY THE MONTH (in inches)

July August September October November December

Greatest Daily Precipitation .83 on the 

25th in 

1902 

1.80 on the 

12th in 

1873 

1.23 on the 

30th in 1921 

2.95 on the 

4th in 1925 

2.68 on the 

9th in 1879 

2.60 on the 

22nd in 1945 

Normal for the Month 

(1971-2000)

.03 .09 .21 .44 1.07 1.31 

Maximum Monthly Precipitation 1.29 in 

1865 

2.13 in 

1977 

2.58 in 1939 4.98 in 2004 5.82 in 1965 9.26 in 1921 

Minimum Monthly Precipitation 0 in 2004* 0 in 2004* 0 in 2001* 0 in 2001* 0 in 1956* 0 in 1930* 

Normal Seasonal1 through 

the Month

.02 .12 .36 .73 2.18 3.75 

Maximum Seasonal1 through the 

Month

1.29 in 

1865 

2.14 in 

1977 

2.58 in 1939 3.68 in 1925 6.13 in 1965 12.73 in 

1965 

Minimum Seasonal1 through the 

Month

0 in 2002* 0 in 1995* 0 in 1883* 0 in 1871 .02 in 1962 .24 in 1962 

Greatest in 5 minutes 

(through 1991) 

.07 on the 

25th in 

1902 

.15 on the 

14th in 

1983 

.20 on the 

22nd in 1905 

.20 on the 

10th in 1966 

.32 on the 

21st in 1967 

.31 on the 1st 

in 1947 

Greatest in 10 minutes 

(through 1991) 

.12 on the 

25th in 

1902 

.16 on the 

14th in 

1983 

.34 on the 

7th in 1957 

.28 on the 

10th in 1966 

.51 on the 

21st in 1967 

.47 on the 

20th in 1921 

Greatest in 15 minutes 

(through 1991) 

.15 on the 

25th in 

1902 

.16 on the 

14th in 

1983 

.35 on the 

7th in 1957 

.40 on the 

7th in 1939 

.65 on the 

27th in 1939 

.54 on the 

10th in 1965 

Greatest in 30 minutes 

(through 1991) 

.20 on the 

25th in 

1902 

.31 on the 

16th in 

1977 

.36 on the 

7th in 1957 

.41 on the 

7th in 1939 

.81 on the 

21st in 1967 

.85 on the 

10th in 1965 

Greatest in 60 minutes 

(through 1991) 

.25 on the 

25th in 

1902 

.48 on the 

16th in 

1977 

.41 on the 

24th in 1958 

.57 on the 

10th in 1966 

.95 on the 

21st in 1967 

1.36 on the 

10th in 1965 

Greatest in 2 hours 

(through 1991) 

Incomplete data .63 on the 

16th in 

1977 

.55 on the 

25th in 1986 

.83 on the 

10th in 1986 

1.11 on the 

21st in 1967 

1.77 on the 

10th in 1965 

Greatest in 24 hours .83 on the 

24-25 in 

1902 

2.13 on the 

16-17 in 

1977 

1.50 on 9/30-

10/1 in 1921 

3.24 on 4-5 

in 1925 

2.75 on the 

9-10 in 1879 

3.62 on the 

23-24 in 

1940 

* Last of Several Occurrences 

1

 The season begins on July 1st
68

RETURN PERIOD1

 - MAXIMUM PRECIPITATION

Return Period 

in Years 

5 

Minutes 

10 

Minutes 

15 

Minutes 

30 

Minutes 

1 

 Hour 

2 

Hours 

24 

Hours 

2 .17 .25 .31 .42 .54 .70 1.62 

5 .23 .34 .43 .59 .76 1.01 2.23 

10 .27 .40 .50 .70 .91 1.21 2.63 

20 .30 .46 .58 .81 1.05 1.40 3.02 

25 .31 .48 .60 .84 1.09 1.46 3.14 

40 .34 .51 .65 .91 1.18 1.58 3.39 

50 .35 .53 .67 .94 1.22 1.64 3.50 

100 .38 .59 .74 1.04 1.35 1.82 3.86 

200 .41 .64 .81 1.14 1.47 1.99 4.21 

1,000 .49 .76 .97 1.36 1.76 2.39 5.01 

10,000 .59 .92 1.18 1.67 2.16 2.94 6.11 

Theoretical 

Max Ever 

1.10 1.75 2.25 3.19 4.13 5.67 11.60 

 1 A return period is defined as a statistical parameter used in frequency analysis as a 

 measure of the average time interval between the occurrence of a given quantity and 

 that of an equal or greater quantity.
69

 2.0 INCHES OR MORE LESS THAN OR EQUAL TO .50

Amount Date Amount Date Amount Date

9.09 1993 2.34 1899 0.5 1853

8.06 1995 2.32 1867 0.49 1975

7.56 1916 2.2 1967 0.46 1984

7.33 1895 2.16 1905 0.44 1873

6.95 1886 2.15 1935 0.43 1920

6.26 1943 2.1 1983 0.42 1945, 1989

5.95 1978 2.08 1901 0.4 1965

5.82 1979 2.03 1941 0.35 1885, 1947, 1968

5.58 1980 2.02 1921 0.34 2004

5.56 1862 2 1910 0.32 1863, 1927

5.05 1866 0.3 1934, 1971

4.91 1915 0.29 1894

4.8 1957 0.26 1857, 1924

4.78 1969 0.21 1928, 1942

4.53 1882 0.18 2000

4.49 2005 0.11 1963

4.32 1917, 1933 0.08 1925, 1959

4.24 1952 0.07 1972

3.9 1930 0.04 1887, 1904, 1864

3.72 1931 0.03 1851

3.59 1914, 1955 0.02 2003

3.57 1909 T 1948, 1976

3.56 1949 0.00 1850, 1859

3.54 1879

3.45 1922

3.37 1868

3.35 1911

3.31 1950

3.3 2001

3.27 1907

3.13 1897

3.11 1874

3.02 1997

2.99 1960

2.96 1974

2.88 1869

2.8 1908

2.79 1890

2.76 1954

2.71 1962, 1982

2.68 1998

2.52 1990

2.47 1876

2.38 1875, 1939

SIGNIFICANT MONTHLY RAINFALL FOR JANUARY
70

SIGNIFICANT MONTHLY RAINFALL FOR FEBRUARY

 2.0 INCHES OR MORE LESS THAN OR EQUAL TO .50

Amount Date Amount Date Amount Date

9.05 1884 2.5 1864 0.5 1951, 1957

7.65 1998 2.46 1991 0.49 1894

6.68 1927 2.44 1876 0.47 1893

5.9 1905 2.41 1908 0.45 1881, 1907

5.83 2005 2.4 1913 0.44 1858

5.4 1976 2.38 2001 0.43 1947

5.31 1941 2.33 1926 0.37 1875, 1964

5.18 1936 2.27 1903 0.35 1921

5.15 1932 2.26 1981 0.31 1997

4.92 1911 0.3 1899, 1925

4.88 2003 0.22 1956, 1968

4.84 1891 0.2 1853

4.83 1878 0.19 1910

4.77 1901 0.18 1877

4.73 1993 0.17 2002

4.54 1935 0.15 1958

4.51 1887 0.1 1972

4.47 1980 0.09 1984

4.34 1969 0.06 1898, 1961, 1977

4.22 1937 0.04 1974

4.21 1873 0.03 1900

4.11 1931 0.02 1885, 1896, 1933

3.88 1983 T 1924

3.76 1959 0.00 1912, 1967

3.73 1874

3.68 2000

3.65 1944

3.62 1915

3.59 1855

3.56 1940

3.43 1866

3.34 1992

3.26 1938

3.15 1958

3.08 1962

3 1865

2.96 1892

2.87 1920

2.81 2004

2.75 1994

2.72 1897

2.64 1978

2.62 1906
71

SIGNIFICANT MONTHLY RAINFALL FOR MARCH

 1.50 INCHES OR MORE LESS THAN OR EQUAL TO .50

Amount Date Amount Date Amount Date

7.88 1867 1.79 1965 0.5 1951

6.96 1991 1.78 1876, 1925 0.46 1872, 2002

6.57 1983 1.7 1974 0.45 1875

6.23 1884 1.66 1943 0.42 1913, 1932

5.89 1941 1.62 1907 0.41 1883, 1890

5.72 1912 1.6 1948 0.38 1955

5.5 1893 1.59 1856 0.36 1914

5 1978 1.55 1968 0.34 1851, 1923

4.97 1952 1.53 1897 0.33 1863, 1870, 1915

4.74 1982 1.52 1853 0.27 1891

4.68 1906 1.5 1970 0.26 1917

4.57 1918 0.25 1990

4.42 1992 0.24 1934

4.31 1954 0.22 2004

3.98 1958 0.2 1859, 1864, 1971

3.81 1995 0.17 1966

3.79 1975 0.15 1860

3.74 1981 0.13 1933

3.73 1886, 1938 0.11 1873

3.71 1979 0.1 1879

3.67 1994 0.06 1931

3.12 1986 0.05 1861

3.02 1930 0.04 1984

2.98 1905 0.02 1877

2.89 1896 0.01 1871

2.79 1888 T 1956, 1959, 1972

2.71 1980 0.00 1857, 1865, 1997

2.67 1946

2.65 1937

2.62 1909

2.46 1920

2.41 1924

2.26 1973

2.21 1998

2.2 1889

2.17 1904

2.12 2005

2.05 1927

2.03 1945

1.98 1869

1.91 1942

1.88 1854, 1881

1.87 1852

1.86 1902
72

SIGNIFICANT MONTHLY RAINFALL FOR APRIL

 .75 INCHES OR MORE LESS THAN OR EQUAL TO .20

Amount Date Amount Date

5.37 1926 0.2 1870, 1964

3.71 1988 0.19 1889

3.58 1965 0.17 1858, 1922

3.35 1941 0.15 1904

2.91 1878 0.14 1928

2.84 1884 0.13 1863, 1907, 1937, 1948

2.24 1967 0.12 1875, 1989

2.17 1856 0.11 1866, 1894, 1895

2.14 1887 0.1 1873, 1888

2.13 1912 0.09 1850, 1949, 1954, 1970

2 1975 0.08 1910, 1913

1.95 1886, 1951 0.06 1876

1.75 1933 0.05 1890, 1973, 1991

1.74 1983 0.04 1857, 1861, 1921

1.65 1958 0.03 1945

1.62 1999 0.02 1897, 1909, 1972, 1974, 1979

1.56 1956 0.01 1864, 1901, 1916, 1934, 

1.54 1952 1962, 1977

1.52 1855 T 1918, 1961, 1966

1.41 2003 0.00 1993

1.4 1903, 1942

1.38 1931

1.35 1881

1.34 1880

1.33 1976

1.26 1900

1.2 1868, 1885

1.18 1980

1.17 1986

1.15 1915

1.11 1925, 1998

1.06 1917, 1930

1.05 1862, 1923

1.02 1935

0.98 1906

0.96 1995

0.93 1971, 1994

0.9 1955

0.89 1854

0.87 1851

0.85 1852, 1914

0.84 1957

0.78 1987

0.77 1924

0.76 1891, 1990, 2001
73

SIGNIFICANT MONTHLY RAINFALL FOR MAY

 .25 INCHES OR MORE LESS THAN .02

Amount Date Amount Date

2.54 1921 0.01 1911, 1916, 1926, 1932, 1939, 

2.17 1884 1946, 1948, 1954, 1961, 1970, 

2.1 1853 1974, 1975, 1982, 1983, 1991, 1993

1.81 1930 T 1879, 1909, 1918, 1936, 1940, 1941

1.79 1977 1959, 1965, 1973, 1985, 1997, 

1.45 1900 2000, 2004

1.25 1864 0.00 1850, 1858, 1861, 1865, 1923, 

1.15 1892 1924, 1951, 1952,1984, 1986

1.14 1883

0.95 1971

0.88 1957

0.77 1901

0.72 1906

0.71 1851

0.66 1898

0.65 1980

0.64 1998

0.62 1962

0.61 1885

0.59 1995

0.58 1878

0.53 1933

0.51 1990

0.49 1955

0.47 1887

0.44 1920

0.43 1877

0.41 1949

0.4 1958

0.39 1893

0.36 1922, 1928

0.35 1891, 1905

0.34 1871, 1919

0.33 1869

0.32 1852, 1874, 1937

0.31 1917

0.3 2003

0.29 1856

0.28 1870, 1915

0.27 1976
74

SIGNIFICANT MONTHLY RAINFALL FOR JUNE

 .05 INCHES OR MORE LESS THAN .02

Amount Date Amount Date

0.87 1990 0.01 1851, 1854, 1864, 1865, 1894, 1896, 1911,

0.68 1850 1926, 1931, 1932, 1936, 1937, 1938, 1942, 

0.48 1862 1943, 1965, 1971, 1979, 1980, 1983, 

0.47 1934 T 1877, 1893, 1897, 1902, 1903, 1905, 1909

0.46 1995 1914, 1915, 1916, 1917, 1921, 1922, 1924, 

0.41 1993 1929, 1940, 1941, 1947, 1949, 1950, 1951,

0.38 1972 1955, 1956, 1958, 1959, 1960, 1961, 1966,

0.31 1884 1968, 1970, 1973, 1978, 1983, 1985,

0.28 1963 1986, 1987, 1991, 1994, 1997, 2000, 2002,

0.27 1899 2003

0.26 1957 0.00 1852, 1855, 1856, 1859, 1863, 1866, 1867, 

0.19 1858, 1861, 1907 1868, 1869, 1870, 1871, 1872, 1873, 1874, 

0.17 1995 1890, 1895, 1904, 1908, 1910, 1919, 1935,

0.16 1878, 1912, 1967 1939, 1946, 1981, 1988, 1996, 2001

0.15 1925, 1945 2004

0.14 1952, 1953

0.13 1892

0.12 1927

0.1 1889, 1944, 1998

0.09 1913, 1928, 1962

0.08 1883, 1900, 1933, 1964

0.07 1879, 1882, 1886

0.06 1880, 1885, 1918, 1989

0.05 1853, 1860, 1876, 1881, 1891
75

 SIGNIFICANT MONTHLY RAINFALL FOR JULY 

Amount (In Inches) Date 

 1.29 1865 

 0.92 1902 

 0.51 1868 

 0.24 1991 

 0.2 1998 

 0.19 1984 

 0.16 1905, 1937 

 0.14 1860, 1912 

 0.13 1968 

 12 1874, 1911 

 0.11 1862, 1864 

 0.09 1880, 1979, 1996 

 0.08 1950 

 0.07 1854 

 0.06 1913, 1941 

 0.05 1869, 1995 

 0.04 1870 

 0.03 1859, 1876, 1907, 1987, 1992, 

 1993, 1994 

 0.02 1916, 1933, 1965, 1976, 2005 

 0.01 1887, 1888, 1897, 1910, 1922, 

 1923, 1936, 1967, 1974, 

 1983 

 T 1885, 1886, 1889, 1891 

 1893, 1896, 1901, 1906, 1909, 

 1915, 1917, 1918, 1919, 1920, 

 1921, 1925, 1926, 1928, 1930, 

 1931, 1932, 1934, 1935, 1938, 

 1939, 1940, 1944, 1945, 1948, 

 1949, 1952, 1953, 1954, 1955, 

 1956, 1957, 1958, 1959, 1960, 

 1961, 1962, 1966, 1969, 1970, 

 1971, 1972, 1973, 1975, 1977, 

 1980, 1981, 1986, 1988, 1990, 

 1997, 1999, 2001, 2003 

 0.00 1850, 1851, 1852, 1853, 1855, 

 1856, 1857, 1858, 1861, 1863, 

 1866, 1867, 1871, 1872, 1873, 

 1875, 1877, 1878, 1879, 1881, 

 1882, 1883, 1884, 1890, 1892, 

 1894, 1895, 1898, 1899, 1900, 

 1903, 1904, 1908, 1914, 1924, 

 1927, 1929, 1942, 1943, 1946, 

 1947, 1951, 1963, 1964, 1978, 

 1982, 1985, 1989, 2000, 2002, 2004 

 

 *This is all of the measurable precipitation for July 
76

 SIGNIFICANT MONTHLY RAINFALL FOR AUGUST 

Amount (In Inches) Date 

 2.13 1977 

 1.95 1873 

 1.36 1854 

 0.87 1945 

 0.85 1951 

 0.64 1908 

 0.4 1852 

 0.39 1983 

 0.32 1880 

 0.3 1867 

 0.28 1936 

 0.26 1912 

 0.21 1853, 1875 

 0.18 1872, 1935 

 0.14 1967 

 0.13 1885, 1896 

 0.11 1918, 1955 

 0.1 1866, 1906 

 0.08 1931 

 0.07 1870, 1899 

 0.06 1876, 1984 

 0.05 1892, 1910, 1926, 1992 

 0.04 1855, 1858, 1889, 1894, 1961 

 0.03 1928, 1938, 1941, 1971 

 0.02 1857, 1913, 1934, 1972, 2005 

 0.01 1881, 1916, 1919, 1920, 1925, 1927, 

 1933, 1969, 1976, 1979, 1987, 1990, 

 1991, 1994, 1995, 2000 

 T 1878, 1882, 1884, 1886, 1887, 1888, 

 1890, 1897, 1900, 1901, 1902, 1903, 

 1904, 1909, 1917, 1921, 1922, 1923, 

 1924, 1930, 1939, 1940, 1942, 1943, 

 1944, 1946, 1949, 1952, 1953, 1954, 

 1956, 1957, 1958, 1959, 1962, 1963, 

 1964, 1965, 1968, 1973, 1974, 1975, 

 1978, 1982, 1985, 1988, 1989, 1993, 

 1996, 1998, 2002, 2003 

 0.00 1850, 1851, 1856, 1859, 1860, 1861, 

 1862, 1863, 1864, 1865, 1868, 1869, 

 1871, 1874, 1877, 1879, 1883, 1891, 

 1893, 1895, 1898, 1905, 1907, 1911, 

 1914, 1915, 1929, 1932, 1937, 1947, 

 1948, 1950, 1960, 1966, 1970, 1980, 

 1981, 1986, 1995, 1997, 1999, 2001, 2004 

 

 *This is all of the measurable precipitation for August 
77

SIGNIFICANT MONTHLY RAINFALL FOR SEPTEMBER

 .10 INCHES OR MORE LESS THAN .10

Amount Date Amount Date

2.58 1939 0.09 1854

1.9 1963 0.08 1891, 1918, 1920,

1.59 1861 1940, 1967

1.24 1921 0.07 1856, 1884, 1898

1.04 1986 0.06 1901, 1960

1 1976 0.05 1868

0.85 1997 0.04 1881, 1888, 1927, 1936,

0.72 1978 1943, 1951, 1959

0.7 1987 0.03 1876, 1923, 1945, 1981, 1996,

0.65 1890 1998

0.62 1958 0.02 1851, 1909, 1913, 1933, 1973,

0.5 1905 1999

0.44 1972 0.01 1857, 1882, 1894, 1895, 1935

0.39 1875 T 1877, 1885, 1887, 1889,1892,

0.38 1982 1896, 1897, 1900, 1902, 1903,

0.37 1957 1904, 1914, 1915, 1917, 1928,

0.36 1863 1930, 1931, 1937, 1944, 1946,

0.31 2002 1948, 1949, 1950, 1952, 1953,

0.29 1965 1955, 1956, 1961, 1966, 1968,

0.28 1941, 1991 1969, 1970, 1971, 1974, 1975,

0.26 1919, 1929 1977, 1980, 1984, 1988, 1990,

0.25 1916 1993, 1994, 1995, 2000, 2004

0.23 1989 0.00 1850, 1852, 1853, 1855, 1859,

0.21 1983 1860, 1862, 1864, 1865, 1866,

0.2 1908, 1985 1867, 1869, 1870, 1871, 1872,

0.18 1934, 1947 1873, 1878, 1879, 1880, 1883,

0.17 1910 1886, 1893, 1899, 1907, 1912,

0.13 1874 1922, 1924, 1925, 1926, 1932,

0.12 1906 1938, 1942, 1954, 1962, 1964,

0.1 1858, 1911, 2005 1979, 1992, 2001, 2003
78

SIGNIFICANT MONTHLY RAINFALL FOR OCTOBER

 .25 INCHES OR MORE LESS THAN .01

Amount Date Amount Date Amount Date

4.98 2004 0.34 1867, 1946 Trace 1887, 1894, 1913, 1937

3.67 1925 0.31 1885 1944, 1945, 1952, 1955,

2.9 1941 0.3 1900 1988, 1990, 1995, 2003

2.12 1889 0.29 1879, 1984, 1985 0.00 1853, 1856, 1860, 1863,

2.01 1883 0.28 1901, 1911 1866, 1868, 1871, 1872,

1.86 1936 0.27 1854, 1895, 1942 1873, 1875, 1898, 1909, 

1.76 1927, 1957 0.26 1888 1915, 1929, 1954, 1967, 

1.74 1987 0.25 1905 1992, 1999, 2001

1.71 1907

1.66 1971

1.54 1870

1.5 1940

1.39 1986

1.35 1910

1.32 1948

1.24 2000

1.1 1932

1.06 1897

1.05 1914

1.04 1919

1.03 1974

0.97 1896

0.96 1878

0.94 1996

0.89 1862, 1912

0.87 1916

0.81 1877

0.8 1966

0.73 1979

0.69 1991

0.68 1951, 1956

0.67 1921

0.61 1939

0.58 1972

0.53 1874, 1880

0.5 1977

0.49 1857

0.47 1858, 1989

0.46 2005

0.42 1918, 1934

0.41 1882

0.4 1983

0.38 1976
79

SIGNIFICANT MONTHLY RAINFALL FOR NOVEMBER

 ONE INCH OR MORE LESS THAN .10

Amount Date Amount Date Amount Date

5.82 1965 1.22 1856 0.1 1891, 1948

4.93 1944 1.19 1861, 1895 0.09 1989

4.92 1985 1.17 1997 0.08 1917

3.53 1967 1.16 1925, 1949, 1986 0.07 1935

3.38 1905 1.04 1930, 1939 0.06 1877, 1971

3.16 1972 1.01 1960, 1964 0.05 1862, 1907, 1916,

2.88 1860 1 1908 1927, 1977, 1991

2.82 1850 0.04 1854, 1876, 1999

2.77 1879 0.03 1933, 1943, 1992

2.53 1946 0.02 1897, 1911, 1937,

2.41 1864 1938, 1959

2.39 1909 0.01 1962

2.37 1984 T 1878, 1903, 1929

2.32 1869 0.00 1872, 1894, 1904,

2.25 1875 1956, 1980

2.23 1913, 1941

2.16 1857

2.15 1855

2.1 1982

2.09 1978

2.08 1887

2.05 1970

2 1868

1.95 1931, 1934

1.94 1983

1.91 1918

1.85 1963

1.83 1888, 1952

1.79 1981

1.7 1996

1.63 1973

1.56 1885

1.53 1902

1.49 1859

1.45 1852

1.43 1900

1.39 1988

1.33 1871, 1987

1.28 1853

1.23 1950, 1951
80

SIGNIFICANT MONTHLY RAINFALL FOR DECEMBER

 TWO INCHES OR MORE .10 INCHES OR LESS

Amount Date Amount Date

9.26 1921 0.1 1886, 1963

7.71 1889 0.06 1958

7.6 1943 0.05 1950

6.6 1965 0.04 1863

6.32 1879 0.03 1912, 1953

6.09 1940 0.02 1901, 1979

5.46 1873 0.01 2000

5.12 1884 T 1917

4.57 1927 0.00 1900, 1929, 1930

4.55 1984

4.5 1852

4.45 1936

4.25 1938

4.15 1880

4.02 1906

4.01 2004

3.89 1877, 1926

3.87 1951

3.76 1909

3.74 1851

3.62 1945

3.58 1902

3.56 1931

3.38 1934

3.29 1854

3.27 1971

3.22 1966

3.2 1861

3.1 1858

3.06 1867

3.02 1947

2.99 1860

2.85 1941

2.84 1888

2.73 1987

2.6 1915

2.56 1992

2.46 1904

2.42 1928

2.4 1932

2.38 1948

2.26 1894

2.23 1988

2.22 1970

2.21 1914

2.2 1952, 1974

2.19 1978
81

 DAYS WITH THUNDERSTORMS 

 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1872 2 2 

1873 1 1 

1874 1 1 1 3 

1875 1 1 2 

1876 0 

1877 0 

1878 0 

1879 0 

1880 1 1 2 

1881 0 

1882 1 1 

1883 0 

1884 1 1 2 

1885 2 1 3 

1886 1 2 1 4 

1887 1 1 

1888 1 1 2 

1889 2 2 

1890 0 

1891 0 

1892 1 1 

1893 1 1 2 

1894 1 1 

1895 1 1 

1896 1 1 1 3 

1897 2 1 1 1 5 

1898 1 1 

1899 0 

1900 1 1 

1901 1 1 1 3 

1902 1 1 

1903 0 

1904 2 2 

1905 1 2 1 1 5 

1906 1 1 1 3 

1907 1 1 

1908 1 1 1 1 2 6 

1909 1 1 2 

1910 1 1 2 

1911 3 2 5 

1912 1 2 2 1 6 

1913 3 3 
82

 DAYS WITH THUNDERSTORMS 

 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1914 1 1 2 

1915 1 1 2 

1916 1 1 2 

1917 2 1 1 4 

1918 3 1 1 1 2 8 

1919 1 1 2 

1920 2 2 

1921 1 1 1 3 

1922 2 1 1 4 

1923 3 3 

1924 1 1 2 

1925 1 1 2 4 

1926 1 3 1 1 6 

1927 1 1 1 3 

1928 1 2 1 4 

1929 2 2 

1930 1 1 2 1 5 

1931 2 1 1 1 2 2 9 

1932 1 1 2 

1933 1 2 1 4 

1934 2 2 1 1 6 

1935 1 1 1 1 4 

1936 1 1 2 3 1 2 1 11 

1937 2 1 1 4 

1938 1 1 1 2 5 

1939 3 2 2 7 

1940 1 1 2 

1941 1 4 1 1 1 8 

1942 2 1 3 

1943 1 1 2 4 

1944 1 2 1 2 6 

1945 1 1 1 3 

1946 1 1 

1947 2 1 1 2 6 

1948 1 1 

1949 1 1 

1950 1 1 

1951 2 2 

1952 2 2 

1953 1 1 

1954 1 1 2 

1955 0 

1956 0 
83

 DAYS WITH THUNDERSTORMS 

 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1957 1 1 1 2 2 1 8 

1958 1 3 1 1 1 1 8 

1959 0 

1960 2 2 

1961 1 1 2 

1962 1 1 2 

1963 1 1 

1964 1 1 1 3 

1965 2 2 

1966 1 1 1 1 1 5 

1967 1 2 1 4 

1968 0 

1969 1 1 

1970 0 

1971 1 3 1 5 

1972 1 1 

1973 1 2 3 

1974 0 

1975 1 1 2 

1976 1 1 2 1 5 

1977 2 1 1 4 

1978 1 1 2 

1979 1 1 1 3 

1980 1 1 1 1 1 1 6 

1981 1 1 1 3 

1982 1 1 1 1 4 

1983 2 3 1 6 

1984 1 1 2 

1985 1 1 1 3 

1986 1 2 1 1 1 6 

1987 2 1 1 4 

1988 1 1 2 

1989 1 1 

1990 2 1 2 5 

1991 1 1 1 1 1 5 

1992 1 1 1 1 1 5 

1993 2 1 3 

1994 1 1 1 3 

1995 1 1 1 3 

1996 1 1 1 1 4 

1997 2 1 3 

1998 1 1 1 3 

1999 1 1 
84

 DAYS WITH THUNDERSTORMS 

 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

2000 2 1 1 1 5 

2001 1 1 

2002 1 1 1 3 

2003 0 

2004 0 

2005 1 1 1 3 

Total 33 37 42 23 16 18 33 48 29 35 31 34 379 
85

DAYS WITH THUNDERSTORMS

02468

1012

187218761880188418881892189619001904190819121916192019241928193219361940194419481952195619601964196819721976198019841

Year

Number of Days with Thunderstorms
86

NUMBER OF DAYS WITH FOG1 REPORTED

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1942 11 4 4 6 4 7 4 4 8 8 12 9 81 

1943 8 5 3 9 5 10 12 4 23 17 14 3 113 

1944 4 3 6 1 9 4 7 16 13 6 2 6 77 

1945 11 8 4 12 4 6 10 8 8 8 11 9 99 

1946 11 11 13 8 1 12 8 10 17 7 9 14 121 

1947 10 17 5 5 5 12 15 11 7 3 90 

1948 26 5 1 1 9 2 13 5 14 16 9 8 109 

1949 4 5 4 5 6 2 4 11 11 4 12 12 80 

1950 11 19 12 11 6 7 8 11 11 16 16 24 152 

1951 9 7 5 3 5 2 5 13 19 12 10 11 101 

1952 6 4 10 11 5 14 11 12 23 7 3 106 

1953 12 8 6 4 1 9 5 4 10 6 9 4 78 

1954 14 14 9 13 4 6 9 3 8 16 12 7 115 

1955 7 5 4 6 4 7 6 12 14 13 15 93 

1956 21 5 15 7 2 7 3 11 6 2 11 90 

1957 6 8 5 5 5 12 10 1 10 7 6 7 82 

1958 5 11 4 5 3 4 5 1 12 13 13 19 95 

1959 15 2 8 4 2 7 1 2 15 11 8 75 

1960 7 5 15 7 7 10 9 3 6 10 10 14 103 

1961 6 6 6 8 2 6 4 1 8 7 11 18 83 

1962 9 9 5 14 1 10 3 9 11 13 14 18 116 

1963 4 11 7 5 1 5 5 2 8 3 8 8 67 

1964 4 1 2 4 10 7 5 5 15 5 10 68 

1965 8 8 3 12 3 1 6 4 6 7 11 5 74 

1966 9 5 12 8 3 2 7 1 6 13 13 79 

1967 17 10 8 1 8 7 5 4 1 12 7 8 88 

1968 5 14 2 3 5 5 4 1 12 13 9 73 

1969 11 4 4 2 6 7 8 8 8 4 3 9 74 

1

 - Includes days with dense fog. 
87

NUMBER OF DAYS WITH FOG1 REPORTED

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1970 15 8 5 4 4 5 5 8 5 14 7 80 

1971 10 10 6 5 7 10 6 1 7 8 12 10 92 

1972 12 16 6 1 5 7 2 6 7 6 6 5 79 

1973 7 6 5 1 8 9 8 5 3 10 7 13 82 

1974 9 6 7 7 4 9 2 4 7 7 4 9 75 

1975 12 13 12 4 5 2 4 12 6 7 13 14 104 

1976 4 16 4 3 8 4 3 7 3 9 10 5 76 

1977 8 10 3 9 7 9 9 5 6 16 10 17 109 

1978 15 11 15 4 3 4 5 3 5 16 14 9 104 

1979 10 10 7 4 10 10 8 8 15 9 11 5 107 

1980 20 15 6 7 8 9 12 11 8 17 8 16 137 

1981 18 14 6 2 7 9 2 4 13 6 18 22 121 

1982 12 11 11 4 7 9 7 10 11 4 9 11 106 

1983 10 15 16 8 11 11 8 10 6 7 8 16 126 

1984 8 8 11 7 11 5 3 8 8 7 15 14 105 

1985 8 13 7 15 3 10 5 11 7 9 11 13 112 

1986 14 12 17 4 11 13 6 13 5 15 12 10 132 

1987 8 9 7 8 10 7 4 9 19 18 8 10 117 

1988 8 11 8 14 8 9 6 8 6 18 19 11 126 

1989 11 8 14 2 6 11 10 5 17 15 12 13 124 

1990 10 5 9 10 3 6 5 1 10 15 7 8 89 

1991 11 17 9 6 7 6 10 20 19 18 11 14 148 

1992 12 15 10 11 5 5 12 9 13 17 6 6 121 

1993 17 10 17 10 5 13 4 9 16 13 12 7 133 

1994 12 6 13 12 8 15 7 10 5 10 5 13 116 

1995 19 12 15 8 8 14 20 21 16 21 25 17 196 

1996 15 17 12 12 4 11 16 18 9 18 12 22 166 

1997 18 18 13 9 19 5 9 14 11 5 15 5 141 

1

 - Includes days with dense fog. 
88

NUMBER OF DAYS WITH FOG1 REPORTED

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1998 19 14 14 11 7 5 20 24 12 15 18 14 173 

1999 18 14 9 10 13 19 18 20 16 22 21 12 192 

2000 22 17 17 16 16 10 11 19 11 21 15 19 194 

2001 17 15 22 14 24 24 10 26 24 21 23 15 235 

2002 17 18 15 14 11 19 15 24 21 10 17 20 201 

2003 20 10 14 8 19 21 23 17 24 24 13 19 212 

2004 21 11 18 4 6 1 4 3 9 12 9 14 112 

2005 15 12 12 7 7 3 8 11 11 15 16 16 133 

1

 - Includes days with dense fog.
89

NUMBER OF DAYS WITH DENSE FOG1 REPORTED 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1942 3 1 3 2 9 

1943 3 1 1 2 3 2 1 4 4 4 25 

1944 1 1 3 3 4 12 

1945 5 2 2 1 1 1 3 3 5 23 

1946 4 4 3 1 2 4 1 5 10 34 

1947 6 8 1 3 4 5 6 4 3 40 

1948 17 2 4 3 2 10 5 2 2 47 

1949 2 2 2 1 4 2 10 7 30 

1950 4 10 5 3 1 2 2 1 5 9 13 55 

1951 2 4 2 1 1 8 5 5 1 29 

1952 2 1 5 1 1 2 4 9 3 2 30 

1953 4 4 2 2 3 1 4 20 

1954 5 7 2 4 3 4 8 9 42 

1955 2 3 2 1 1 3 3 3 7 8 33 

1956 9 2 6 2 2 2 4 3 2 5 37 

1957 3 2 5 3 2 1 4 20 

1958 1 2 1 1 3 5 5 7 6 31 

1959 7 7 1 1 7 4 1 28 

1960 1 2 4 4 1 1 3 5 1 5 10 37 

1961 2 2 1 3 4 5 11 28 

1962 6 5 2 8 1 2 1 6 7 9 47 

1963 2 4 1 2 1 3 5 18 

1964 2 1 1 1 1 1 6 1 2 16 

1965 4 2 4 1 5 2 18 

1966 6 2 4 1 1 4 5 6 29 

1967 7 5 1 1 9 4 4 31 

1968 1 5 1 1 1 1 8 8 5 31 

1969 1 2 1 1 2 1 2 3 13 

1970 4 2 3 1 1 1 5 2 19 

1971 4 4 2 2 3 1 1 2 5 24 

1972 5 6 1 1 1 2 16 

1973 2 1 2 3 1 7 2 2 20 

1974 2 1 4 1 2 2 1 5 18 

1975 5 4 1 2 1 3 6 8 30 

1976 1 3 2 3 3 7 19 

1977 5 1 1 1 1 4 4 5 22 

1978 1 2 2 3 2 4 14 

1979 6 2 1 2 1 6 1 3 22 

1980 4 4 1 1 1 2 3 1 9 26 

1981 4 2 1 1 3 7 12 30 

1982 3 3 1 1 1 5 14 

1

 – Visibility of 1⁄4 mile or less 
90

NUMBER OF DAYS WITH DENSE FOG1 REPORTED 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1983 3 1 4 

1984 3 2 1 1 1 1 1 10 

1985 2 3 3 1 1 3 2 6 21 

1986 3 3 3 5 1 2 17 

1987 1 1 1 3 2 8 

1988 1 1 1 3 2 1 1 10 

1989 1 2 2 3 3 4 15 

1990 2 4 1 2 5 1 2 17 

1991 1 2 1 1 1 3 4 2 15 

1992 1 2 1 4 3 11 

1993 3 3 5 2 13 

1994 6 1 1 3 11 

1995 1 3 1 1 8 3 17 

1996 2 4 1 3 2 5 4 4 25 

1997 1 1 2 2 2 8 

1998 1 3 1 3 2 10 

1999 4 3 2 1 2 3 7 2 24 

2000 3 1 1 3 9 17 

2001 4 4 7 2 17 

2002 2 2 4 2 1 11 

2003 6 2 5 4 17 

2004 2 2 2 1 1 5 13 

2005 2 1 1 3 4 11 

1

 – Visibility of 1⁄4 mile or less 
91

DAYS WITH FOG

0

50

100150200250

1942194419461948195019521954195619581960196219641966196819701972197419761978198019821984198619881990199219941996

Year

Number of Days with Fog

Regular Fog Dense Fog
92

NUMBER OF DAYS WITH HAZE REPORTED 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1942 11 7 5 3 5 9 14 4 16 19 21 18 132 

1943 7 0 2 8 14 11 14 6 21 18 19 12 132 

1944 11 6 1 2 8 7 18 25 19 26 11 19 153 

1945 17 8 11 8 5 11 20 18 13 14 9 8 142 

1946 4 4 6 10 6 5 10 13 16 11 7 10 102 

1947 8 15 7 3 10 7 22 9 19 19 8 8 135 

1948 19 7 3 3 8 8 18 22 18 17 12 9 144 

1949 0 6 4 6 2 5 15 13 17 11 12 9 100 

1950 7 16 9 5 3 5 11 15 14 17 8 19 129 

1951 6 9 5 6 8 10 10 19 27 11 12 10 133 

1952 4 4 2 7 15 6 24 21 19 28 10 8 148 

1953 16 9 9 5 1 10 14 17 15 12 17 9 134 

1954 15 8 11 14 11 11 20 8 22 21 16 11 168 

1955 4 9 7 4 6 10 14 14 17 25 13 16 139 

1956 19 8 18 7 8 7 12 10 20 13 11 9 142 

1957 5 17 11 9 4 13 19 14 14 11 14 12 143 

1958 11 8 2 7 14 8 13 13 19 17 15 20 147 

1959 18 3 13 12 0 11 16 9 9 18 12 8 129 

1960 7 5 18 13 7 21 13 10 15 15 10 12 146 

1961 11 11 6 9 1 20 15 19 16 14 15 20 157 

1962 12 8 7 14 7 8 22 24 25 21 18 24 190 

1963 13 21 7 8 6 9 21 16 16 14 14 18 163 

1964 7 5 5 4 15 16 18 17 18 21 7 11 144 

1965 11 11 5 13 10 7 22 19 10 19 13 6 146 

1966 14 10 20 12 10 16 20 8 12 19 17 14 172 

1967 12 13 7 2 13 13 16 25 13 22 17 8 161 

1968 7 20 9 10 10 22 13 11 15 20 17 13 167 

1969 11 8 11 9 19 11 22 27 23 11 7 19 178 

1970 15 10 11 6 15 15 23 21 22 14 18 14 184 

1971 21 19 20 8 12 19 30 17 21 12 21 8 208 

1972 22 18 25 15 17 22 20 21 22 13 13 12 220 

1973 8 18 5 15 22 23 25 29 25 21 12 26 229 

1974 13 13 17 15 17 25 16 22 25 16 20 17 216 

1975 13 13 12 8 24 24 21 23 25 14 15 21 213 

1976 13 11 11 6 13 16 21 14 16 21 14 17 173 

1977 11 15 4 18 5 20 27 19 12 24 15 18 188 

1978 12 10 7 2 11 12 24 16 8 25 11 11 149 

1979 5 10 10 5 7 13 20 11 21 13 14 9 138 

1980 4 16 4 9 7 15 20 17 15 16 16 13 152 

1981 18 14 8 9 8 20 10 22 18 8 19 23 177 

1982 7 11 1 5 9 6 15 23 10 13 13 14 127 

1983 4 10 2 3 16 15 19 14 11 15 11 8 128 

1984 14 7 10 6 18 8 7 8 12 4 11 12 117 

1985 11 11 11 18 7 17 15 15 7 10 10 16 148 
93

NUMBER OF DAYS WITH HAZE REPORTED 

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL 

1986 14 6 11 1 12 14 6 13 5 15 5 11 113 

1987 6 5 5 9 9 11 8 8 21 21 10 10 123 

1988 7 7 5 8 7 7 9 8 3 19 13 2 95 

1989 3 6 8 8 8 11 9 2 13 12 9 11 100 

1990 5 4 10 6 3 8 7 8 10 17 5 0 83 

1991 14 19 1 5 6 10 13 16 18 19 11 9 141 

1992 8 5 5 16 8 6 12 16 18 17 3 3 117 

1993 6 4 11 6 4 11 3 9 15 10 6 6 91 

1994 11 0 9 10 7 16 11 10 9 5 1 6 95 

1995 5 9 4 3 4 15 21 14 12 10 21 13 131 

1996 8 8 5 4 9 10 8 16 14 16 8 3 109 

1997 10 16 14 9 23 10 14 15 12 7 11 4 145 

1998 10 2 10 10 2 7 25 28 14 17 21 13 159 

1999 14 14 14 7 13 21 16 20 22 7 23 14 185 

2000 19 7 11 15 17 16 13 22 16 11 15 21 183 

2001 20 3 15 10 17 18 14 21 23 21 18 15 195 

2002 21 20 17 13 12 20 18 25 19 15 18 20 218 

2003 20 8 14 3 15 12 18 9 22 25 10 11 167 

2004 21 6 20 12 11 17 17 14 13 20 15 17 183 

2005 9 12 14 11 15 11 25 24 19 20 21 26 207 
94

DAYS WITH HAZE

0

50

100150200250

1942194419461948195019521954195619581960196219641966196819701972197419761978198019821984198619881990199219941996

Year

Number of Days with Haze

Days wth Haze
95

AVERAGE DAILY SURFLINE WATER TEMPERATURE FOR MISSION BEACH 

DAY JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

1 58 57 58 60 62 64 65 68 68 65 63 60

2 57 57 58 60 61 64 65 68 68 65 63 60 

3 57 57 58 60 61 64 66 69 68 65 62 60 

4 57 57 58 60 61 64 66 69 68 65 62 59 

5 57 57 58 60 61 64 66 69 67 65 62 59 

6 57 58 58 60 61 64 66 69 67 65 62 59 

7 57 58 58 60 61 64 66 69 67 65 62 59 

8 57 57 58 60 62 64 66 69 67 65 62 59 

9 57 57 58 60 62 64 67 69 67 65 62 59 

10 57 57 58 60 62 64 66 68 67 65 62 59 

11 57 57 58 60 62 64 67 69 67 65 62 59 

12 57 57 59 60 62 64 67 69 67 64 62 59 

13 57 58 58 60 62 65 67 69 67 65 62 59 

14 57 58 59 60 62 65 67 69 67 64 62 59 

15 57 58 59 60 62 65 67 69 66 64 62 59 

16 57 58 59 61 62 64 67 69 67 64 61 58 

17 57 58 59 61 63 65 67 68 67 64 61 58 

18 57 58 59 60 62 65 67 68 67 64 61 58 

19 57 58 59 61 63 65 67 69 67 64 61 58 

20 57 58 59 61 63 65 67 69 67 64 61 58 

21 57 58 59 61 63 65 67 69 66 64 61 58 

22 57 58 59 61 63 65 67 69 66 64 60 58 

23 57 58 59 61 63 65 67 68 66 64 60 58 

24 57 58 59 61 63 65 68 68 66 64 60 58 

25 57 58 59 61 63 65 68 68 66 64 60 58 

26 57 58 59 61 63 65 68 68 66 64 60 58 

27 57 58 59 61 63 65 67 68 66 64 60 58

28 57 58 59 61 64 65 67 68 66 64 60 58

29 57 58 59 61 64 65 68 68 66 63 60 57

30 57 59 61 63 65 68 68 65 63 60 57

31 57 59 64 68 68 63 57 

MEAN 57 58 58.6 60.5 62.4 65 67 68.5 67 64.3 61.3 58.5

ABSOLUTE HIGHEST WATER TEMPERATURE: 78 on August 15 and 18, 1971 

ABSOLUTE LOWEST WATER TEMPERATURE: 47 on March 4, 1975
96

MISSION BEACH MEAN DAILY SURFLINE WATER TEMPERATURE

505560657075

1 31 61 91 121 151 181 211 241 271 301 

Day of the Year

Water Temperature (degrees Fahrenheit)

 Surfline Water Temperature
97

 MEAN MONTHLY WIND DIRECTION FOR EACH HOUR OF THE DAY

A.M. P.M.

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 

January 

NE NE NE NE NE NE NE NE E SE NW NW NW NW NW NW NW NW NW NW NW 

February 

NE NE NE NE NE NE NE E NE S NW W W W NW NW NW NW NW NW NW N

March 

NE NE NE NE E NE NE E NW NW W W W W W W NW NW NW NW NW N

April 

NW NW NE NE E NE E NW S W W W W W W W W NW NW NW NW N

May 

NW SW SW NW NW NW NW S SW W W W W W W W W W NW NW NW N

June 

NW NW NW NW N N NW NW W W W W W W W W W W NW NW NW N

July 

NW NW NW NW NW N NW NW W W W W W W W W W W NW NW NW N

August 

NW NW NW NW NW NW NW NW W W W W W W W W W W NW NW NW N

September 

NW NW NW NW NW NW NW NW NW W W W W W W W NW NW NW NW NW N

October 

NW N N NE NE NE NE NW NW NW W W W W W W NW NW NW NW NW N

November 

NE NE NE NE NE NE NE NE NE NW NW NW NW NW NW NW NW NW NW NW NW 

December 

NE NE NE NE NE NE NE NE E SE NW NW NW NW NW NW NW NW NW NW E 
98

MEAN MONTHLY WIND SPEED FOR EACH HOUR OF THE DAY 

A.M. P.M. 

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 1

January 

4.2 4.3 4.4 4.4 4.4 4.4 4.4 4.3 4.1 4.6 5.5 6.7 8.1 8.8 8.9 8.5 7.2 5.3 4.6 4.5 4.1 4

February 

4.5 4.6 4.7 4.5 4.6 4.7 4.7 4.6 4.8 5.6 6.7 8.1 9.4 10.1 10.2 9.7 8.7 7 5.5 4.8 4.6 4

March 

4.5 4.7 4.7 4.7 4.7 4.6 4.5 4.5 5.2 6.4 7.9 9.2 10.3 10.7 10.6 10.2 9.2 7.8 6.1 5.2 4.8 4

April 

4.5 4.6 4.7 4.6 4.5 4.5 4.4 4.9 5.3 7.4 8.9 10.1 10.9 11.1 10.9 10.3 9.4 8.2 6.8 5.5 4.8 4

May 

4.4 4.4 4.4 4.3 4.3 4.3 4.5 5.1 6.2 7.9 9.4 10.3 10.9 11 10.7 10.1 9.2 8.2 7 5.8 5 4

June 

3.9 4.9 4 4.1 4 4.1 4.3 4.9 6.2 7.8 9.2 10.1 10.7 10.6 10.3 9.7 9 8 6.9 5.8 4.8 4

July 

3.4 3.4 3.5 3.6 3.6 3.6 3.8 4.5 6 7.7 9.2 10 10.5 10.5 10.2 9.6 8.9 8 6.8 5.8 4.7 

August 

3.4 3.4 3.5 3.5 3.4 3.5 3.8 4.2 5.7 7.5 9.1 10.1 10.6 10.6 10.3 9.6 8.8 7.8 6.6 5.5 4.4 3

September 

3.5 3.5 3.5 3.5 3.5 3.5 3.5 4 5.1 7 9 10.2 11 11 10.6 9.8 8.9 7.6 6.1 4.9 4.1 3

October 

3.5 3.6 3.6 3.6 3.7 3.6 3.7 3.7 4.4 6 7.3 9.3 10.3 10.4 10 9.2 7.9 6.2 4.7 4 3.8 3

November 

3.7 3.7 3.7 3.7 3.7 3.8 3.9 3.6 3.8 4.7 6.2 7.9 9.3 9.6 9.5 8.8 7.1 5.1 4.1 3.8 3.7 3

December 

4.2 4.3 4.3 4.2 4.3 4.2 4.2 4.1 3.9 4.5 5.5 6.8 8.1 8.8 8.8 8.2 6.7 5.1 4.4 4.3 4.2 4
99

PEAK WIND GUSTS IN MILES PER HOUR

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV D

1970 20 NW 42 S 28 S 30 NW 24 NW 24 S 22 NW 18 NW 26 NE 23 NW 35 SE 21971 38 W 26 W 30 W 30 NW 24 SW 22 NW 21 NW 22 NW 22 W 28 W 25 SE 31972 22 W 23 S 21 SW 28 NW 24 SW 26 NE 26 S 24 SE 23 SE 29 N 41 W 31973 28 W 33 S 34 W 30 NE 21 S 21 S 20 W 23 SE 20 NW 22 SW 28 W 1974 34 S 23 NE 36 SW 26 W 26 W 21 NW 20 W 19 SE 18 W 30 W 23 W 21975 24 W 23 NE 29 SE 32 SE 23 SW 21 NW 23 S 18 NW 18 NW 21 W 37 W 21976 26 S 32 SE 34 NW 37 W 20 SW 20 NW 21 NW 23 NW 28 S 23 SE 26 W 21977 28 NE 22 NW 31 NW 20 NW 34 S 22 NW 20 NW 29 S 22 NW 22 NW 22 NW 1978 33 S 44 SE 46 S 20 NW 24 NW 32 W 20 NW 19 NW 38 S 27 S 30 S 31979 34 NW 29 NW 30 SE 23 W 25 W 22 SW 21 NW 20 NW 21 NW 30 NW 22 SE 21980 44 S 45 S 33 W 29 N 24 NW 22 NW 21 W 23 SW 22 W 29 W 20 NW 21981 30 SE 24 NW 29 W 28 W 23 SW 23 NW 23 SW 23 NW 35 NW 23 NW 22 S 21982 36 W 32 S 45 SW 34 SW 24 NW 22 NW 20 NW 22 NW 22 S 21 NW 42 NW 31983 35 SW 30 SE 38 S 30 SE 22 W 20 W 20 NW 22 SW 30 S 25 NE 32 NW 21984 38 N 30 N 32 W 32 NW 22 NW 26 SW 23 NW 22 NW 25 S 23 NW 31 SW 41985 29 S 32 W 41 NW 23 NW 28 NW 24 NW 30 SW 24 NW 25 NW 22 W 37 SW 1986 32 S 35 SE 37 S 28 W 28 SW 21 W 21 W 21 NW 28 SE 25 W 35 SE 21987 35 SW 37 W 40 SW 29 SW 30 SW 25 W 26 W 24 SW 25 W 32 SE 30 NE 31988 64 W 36 NE 26 NW 40 SW 40 NW 28 NW 21 NW 22 NW 31 NE 25 S 35 W 31989 35 N 25 NW 35 S 24 NW 31 SW 23 NW 24 S 23 NW 31 NW 29 NW 28 SW 21990 31 W 36 NW 30 NW 30 SW 31 S 24 NW 23 NW 26 N 23 NW 24 NW 36 NW 31991 29 NW 38 SW 43 SW 25 NW 30 SW 24 NW 23 NW 29 SW 25 NW 32 NW 35 N 41992 35 S 37 SE 38 S 26 N 23 NW 23 NW 24 NW 23 SW 21 NW 28 NE 23 SE 31993 43 NW 46 SW 33 SW 22 NW 23 NW 23 SW 20 NW 20 W 23 NW 21 NE 28 NW 31994 29 NW 40 S 35 S 31 W 24 NW 21 SW 22 NW 25 SW 35 W 31 SE 30 NW 21995 52 S 32 S 44 S 35 NW 26 NW 22 SW 24 S 22 NW 21 NW 20 NW 21 NW 1996 33 NW 36 W 29 S 25 NW 25 S 35 W 25 NW 23 W 22 W 32 W 25 SW 1997 33 SE 33 NW 23 NW 29 E 20 W 25 W 23 W 23 NW 24 NW 28 NW 31 W 41998 28 S 45 S 38 S 36 S 32 S 23 W 22 W 23 SE 22 W 23 NW 34 S 31999 24 S 28 W 36 SW 37 SW 28 W 23 W 22 W 21 W 22 W 21 W 21 W 32000 25 W 36 SE 45 SW 32 SE 26 NW 25 SW 22 W 23 W 21 W 24 SE 29 W 32001 37 SE 46 SE 32 SW 33 NW 22 W 22 W 22 W 21 W 23 SE 25 NW 28 S 22002 23 W 22 SW 33 W 24 W 26 W 22 W 22 W 25 NW 22 W 21 NW 37 E 2003 38 E 32 S 36 S 32 S 30 S 24 SW 22 W 21 NW 25 NW 24 W 23 NW 3
100

YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV D

2004 18 W 24 SE 24 S 26 W 21 S 24 S 21 NW 21 W 25 W 39 S 22 W 2005 28 SE 31 S 28 W 28 W 23 W 24 W 21 W 21 W 23 W 21 W 21 S 2
101

PEAK ANNUAL WIND

2025303540455055606570

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

Year

Peak Annual Wind (miles per hour)

Peak Annual Wind 7 Year Moving Average
102

THE NUMBER OF DAYS NOT SATISFYING THE AIR QUALITY STANDARDS IN 

PARTS OF OZONE PER HUNDRED MILLION PARTS OF AIR (PPHM) 

YEAR STATE (75 PPHM) FEDERAL (100 PPHM) 

1978 151 90 

1979 138 70 

1980 167 87 

1981 192 78 

1982 120 47 

1983 125 61 

1984 146 51 

1985 148 50 

1986 138 46 

1987 127 40 

1988 160 45 

1989 158 55 

1990 139 39 

1991 106 27 

1992 97 19 

1993 90 14 

1994 79 9 

1995 96 12 

1996 51 2 

1997 43 1 

1998 54 9 

1999 27 0 

2000 24 0 

2001 29 2 

2002 15 0 

2003 23 1 
103

DAYS NOT SATISFYING AIR QUALITY STANDARDS

0

50

100150200

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

Year

Number of Days

State Standard Federal Standard
NOAA SCIENTIFIC AND TECHNICAL PUBLICATIONS

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