NOAA Technical Memorandum NWS WR-273 

Climate of Flagstaff, Arizona 

Mike Staudenmaier, Jr., Reginald Preston (Retired), and Paul Sorenson (Retired) 

August 2007 

1 National Weather Service Office, Flagstaff, Arizona

United States National Oceanic and National Weather Service 

Department of Commerce Atmospheric Administration David L. Johnson, Assistant Administrator 

Carlos M. Gutierrez, Secretary VADM C. Lautenbacher for Weather Services 

 Under Secretary 
And is approved for publication by 

Scientific Services Division 

Western Region 

Andy Edman, Chief 

Scientific Services Division 

Salt Lake City, UT 

 
CONTENTS

 Page

I. Climate of Flagstaff, Arizona ....................................................................................... 1-4 

II. Temperature Records

Daily Maximum and Minimum Temperature Extremes................................................ 6-17 

Highest and Lowest Average Temperatures by Month ............................................... 18-20 

Warmest and Coldest Winter, Spring, Summer, and Fall............................................ 21-22 

Highest and Lowest Annual Temperatures........................................................................23 

Average Number of Days Per Month with Maximum Temperatures 

80, 85, and 90 Degrees or Higher ..........................................................................24 

Average Number of Days Per Month with Minimum Temperatures 

40, 32, and 0 Degrees or Lower.............................................................................24 

Freeze and Growing Season Data......................................................................................24 

Greatest Number of Consecutive Days with Maximum Temperatures 

85 degrees or Higher..............................................................................................25 

Greatest Number of Consecutive Days with Maximum Temperatures 

90 degrees or Higher..............................................................................................25 

Greatest Number of Consecutive Days with Minimum Temperatures 

32 degrees or Lower ..............................................................................................26 

Greatest Number of Consecutive Days with Minimum Temperatures 

0 degrees or Lower ................................................................................................26 

III. Precipitation Records

Greatest Daily 24-Hour Precipitation (Midnight to Midnight).................................... 28-30 

Maximum and Minimum Precipitation by Months ..................................................... 31-32 

Wettest and Driest Winter, Spring, Summer, and Fall ................................................ 33-34 

Yearly Precipitation Totals ................................................................................................35 

Ranked Wettest and Driest Calendar Years.......................................................................36 

Number of Days with 0.01 Inch and 0.10 Inch 

or More, with Average Number of Days ...............................................................37 

Number of Days with 0.25 Inch and 0.50 Inch 

or More, with Average Number of Days ...............................................................37 

Greatest Number of Consecutive Days with 0.01 Inch 

and 0.25 Inch or More............................................................................................38 

Greatest Number of Consecutive Days with 0.50 Inch 

and 0.75 Inch or More............................................................................................39 

Greatest Number of Consecutive Days without Measurable Precipitation .......................39 

Excessive Storms ...............................................................................................................40 

III. Precipitation Records (continued)
Greatest Daily 24-Hour Snowfall ................................................................................ 41-43 

Maximum Monthly Snowfalls ..................................................................................... 44-45 

Average First and Last Snowfall Dates .............................................................................45 

Seasonal Snowfall Totals...................................................................................................46 

Ranked Snowiest and Least Snowiest Seasons..................................................................47 

Number of Days with One Inch and Four Inch 

or More Snowfall, with Average Number of Days................................................48 

Number of Days with Six Inch and Ten Inch 

or More Snowfall, with Average Number of Days................................................48 

Ranked Snowiest Calendar Days.......................................................................................49 

Snowiest Two Calendar Day Events .................................................................................49 

Excessive Snowstorms.......................................................................................................50 

Average Number of Days with Snowfall of One Inch or More.........................................51 

Average Number of Days with Thunderstorms.................................................................51 

IV. Miscellaneous Information

Statistics on Sunshine, Cloudiness, and Fog......................................................................53 

Normal Heating and Cooling Degree Days .......................................................................54 

Monsoon Statistics.............................................................................................................55 

Normal Daily Maximum, Minimum, and Mean Temperatures................................... 56-68 

Sunrise and Sunset Table for Flagstaff, Arizona ...............................................................69 

I. CLIMATE OF FLAGSTAFF, ARIZONA 
2 

NARRATIVE GEOGRAPHICAL AND CLIMATOLOGICAL SUMMARY 

Flagstaff is majestically located on a plateau in the center of the largest stand of 

Ponderosa Pine in the United States, at the base of the San Francisco Peaks (Arizona=s highest 

mountains - 12,633 feet). The plateau, with an average elevation of around 7000 feet, is the 

southern edge of the Colorado Plateau and curves from the Grand Canyon southeastward across 

central Arizona and then eastward into New Mexico. Flagstaff is the hub for north-south and 

east-west travel across northern Arizona, and is the >gateway= to numerous recreational areas in 

Arizona, including the Grand Canyon. 

Flagstaff=s elevation of 7000 feet ensures a variety of weather including cold winters and 

mild pleasant summers, moderate humidity, and considerable diurnal temperature changes. Only 

limited farming is carried on because of the shortness of the growing season, even though the 

average precipitation for Flagstaff is 22.91 inches. The average date of the last occurrence of 

320

F in the spring is June 10 and that of the first 320F temperature in the fall is September 21. 

However, the summers in Flagstaff are one of its best kept secrets with an average maximum 

temperature in July of 82.20

F, and an all-time record high of 970F. On average, only four days in 

the summer have maximum temperatures of 900F or higher. Summer minimum temperatures are 

cool and refreshing with temperatures often dipping into the 40s with an occasional night in the 

30s. 

The moderate summer heat gives way to a cooler but nonetheless pleasant fall period 

with maximum temperatures generally in the 60s with minimum temperatures falling below 

freezing. Winter weather typically begins by November and becomes well entrenched by 

December, with frequent light to moderate snows and increasingly colder weather. By 

December, minimum temperatures are generally in the teens; however afternoon maximum 

temperatures still average in the 40s, due to the amount of sunshine the station receives. Because 

of its location with respect to the typical jetstream and its high altitude, Flagstaff is one of the ten 

sunniest locations of National Weather Service offices in the United States, averaging 78 percent 

of the possible sunshine throughout the year. Even with all of this winter sunshine, significant 

snowfall can be expected during the winter with an average snowfall of around 110 inches per 

year. Between storms, when dry high pressure builds in, winds become light, and fresh snow 

cover is on the ground, minimum temperatures can plummet. The all-time record low for 

Flagstaff is -300

F. 

By mid-April, winter weather usually begins to break, and although snow is not 

uncommon in May, warm spells become more frequent. Spring in Flagstaff is typically breezy 

and dry with little precipitation occurring in May and early June. Due to the very dry airmass 

typical of the late spring months, late season frosts and freezes are still a possibility, with 320

F 

temperatures being recorded as late as July 8. Snowfall has been reported as late as the middle 

of June. 

There are two distinct periods of precipitation in Flagstaff. The first occurs during the 

winter months from November through April when the jetstream can be located over the state 

allowing Pacific storm systems to move overhead. The other distinct period is classified as the 

summer rainy season, or >summer monsoon.= The monsoon rainy period usually occurs during 

July and August when most of Arizona is subjected to widespread thunderstorm activity. These 

thunderstorms are extremely variable in intensity and location and occur mainly between the 
3 

hours of 11 a.m. and 6 p.m. Some of these storms can reach severe levels, with large hail, 

damaging winds, and occasionally even a tornado. 

Prevailing winds at Flagstaff are southerly most of the year. This is due to terrain 

influences and short-wave weather disturbances moving across the Great Basin region of the 

West. Strong winds of 40 mph or greater are likely during the spring months, especially when 

low pressure moves into the Great Basin and eastward across southern Utah. Winds of damaging 

force (greater than 60 mph) are rare but may occur around some of the mountain locations during 

the winter and spring months. Additionally, some thunderstorms may produce local wind gusts 

over 60 mph for short durations. 

Since there is no concentration of industry, pollution is almost nonexistent, and the air is 

remarkably free of contaminants of any kind, although smoke from resident=s fireplaces can 

become a problem on some of the colder nights due to strong radiational inversions that develop. 

During the spring and fall months, prescribed burns take place in the region, contributing to 

occasional smoke and haze issues. During the winter and spring months, fog occasionally forms 

due to radiational cooling from snow cover on the ground. However, this fog usually breaks up 

quickly by morning. In spite of the elevation, periods of low ceilings and limited visibilities are 

usually of short duration. 

A HISTORY OF WEATHER OBSERVATIONS AT FLAGSTAFF 

The first official weather station in Flagstaff was established September 9, 1898. The 

office was located at the southeast corner of Aspen Avenue and Park Street in a one-story fiveroom brick building known as the AMilligan Cottage@. The first observer was Miss Elizabeth 

Renoe, who later married a young attorney who became the first United States Senator from 

Arizona, Senator Henry Ashurst. 

On March 15, 1912, the station was moved to Sitgreaves and Ellery Streets, which was 

one-half mile southeast of the previous location. The station remained at this location until 

October 29, 1919. The station was then moved to 602 North Leroux Street. 

On June 1, 1943, the weather station was moved to the Federal Post Office Building in 

downtown Flagstaff. A first-order weather station was then established. 

On January 12, 1950, the weather station was moved to the Flagstaff Municipal Airport, 

six miles south of Flagstaff. The station and the weather office remained at the airport until June 

1994 when the National Weather Service office moved to the Camp Navajo Army Depot in 

Bellemont, 10 miles west of Flagstaff. From July 1994 to July 1995, the National Weather 

Service office was temporarily located in the army barracks, while a new office was constructed. 

On July 21, 1995, the office officially moved to its current location on the Camp Navajo Army 

Depot. An automated weather station (ASOS) remains at the Flagstaff Municipal Airport 

recording the official observations for Flagstaff. The ASOS was commissioned July 1, 1994. 

SOME HIGHLIGHTS OF THE WEATHER RECORDS IN FLAGSTAFF 

Many unusual weather events have taken place in Flagstaff since official weather 
4 

observations began on September 9, 1898. The following is a brief description of some of the 

more extreme conditions recorded since then. 

The all-time record high temperature for Flagstaff of 970

F occurred on July 5, 1973. 

Skies were clear and winds were generally light westerly, although by afternoon winds were 

generally around 10 mph. The early morning temperature of 510F was very close to the normal 

of 480

F. The next day a weak cold front approached the state, keeping the afternoon high 

temperature only at 890F. 

The all-time record warmest minimum temperature for Flagstaff was broken on back to 

back nights in 2002. On July 1, 2002 the mercury fell to only 67 degrees breaking the previous 

record of 66 degrees set in 1949. This record was then broken again the next night when the 

temperature only fell to 68 degrees. Oddly enough, the dew point temperatures were only in the 

lower 40s during this period and there were not extensive clouds or winds to keep the 

temperatures from falling rapidly. However, there was a large fire burning to the east of 

Flagstaff, with some smoke in the area that may have contributed to the record warm overnight 

temperatures. 

The longest consecutive stretch of days with maximum temperatures of 900F or greater in 

Flagstaff was 11 days. This occurred during June 21 - July 1, 1990. The highest temperature 

reached during this longest stretch of warm weather was 940F. 

The longest consecutive stretch of days with maximum temperatures of 850F or greater in 

Flagstaff was 22 days. This occurred during June 10 - July 1, 1974. 

The maximum number of days in a calendar year with temperatures of 900F or greater 

was 15 set in 1974. Of note, 14 of those days occurred in June. The maximum number of days 

in a year with temperatures of 850F or greater was 48 days which was also set in the warm 

summer of 1974. 21 of these days occurred in June of that year. 

The coldest temperature ever recorded in Flagstaff was -300F which was observed on 

January 22, 1937. The maximum temperature reached that day was +120

F, which was a 420F 

diurnal spread. 

The maximum number of consecutive days with minimum temperatures of 00

F or lower 

was eight. This stretch of cold weather occurred from December 27, 1966 - January 3, 1967. 

The maximum number of days in a calendar year with temperatures of 00F or lower was 

23 set in 1932. The maximum number of days in any month with temperatures of 00

F or lower 

was 17 set in the extremely cold month of January 1937. The average minimum temperature that 

month was -2.90

F which was about 18 degrees below normal. 

Snowfall in Flagstaff is highly variable as well. The most snowfall ever recorded during 

the snow season (July - June) was 210.0 inches in 1972-73. On the other extreme, the least 

snowfall ever recorded during the snow season was 11.2 inches which was set in 1933-34. 

The all-time record for heaviest precipitation during any calendar day at Flagstaff was 

3.93 inches which was set on February 19, 1993. Interestingly enough, this precipitation all fell 

in the form of rain, with temperatures remaining in the middle and upper 30s through the entire 
5 

24 hours. Another 1.18 inches of precipitation fell the next day; however temperatures fell 

during the morning hours, changing the rain to snow, with a snow accumulation of 3.2 inches by 

the end of the day. 

February 1993 was the wettest month on record, with 10.05 inches of precipitation falling 

during that month. Additionally, January 1993 was the wettest January on record with 9.55 

inches of precipitation falling. Thus, almost 20 inches of precipitation (or almost the entire 

normal precipitation expected for a year at Flagstaff) fell in a two month period of time. 

December 1992 was the second wettest December on record, giving a three month total from 

December 1992 through February 1993 of 27.38 inches which is by far the wettest three month 

period of time in Flagstaff climatological history. Needless to say, this period was known for the 

magnitude of flooding which occurred across the area. 

The most snowfall to occur within a continuous stormy period occurred from December 

13 through December 20, 1967, when 84.6" of snow was recorded. By the end of this event, 83 

inches of snow lay on the ground, essentially paralyzing the city of Flagstaff and most of 

northern Arizona for over a week. Because of snow compaction and limited means to measure 

this amount of snowfall, it was likely that considerably more snow than the recorded amount 

actually fell during this event. 

The greatest number of consecutive days without measurable precipitation was recorded 

from September 24 through December 31, 1999, a total of 99 days! The greatest number of 

consecutive days with measurable precipitation was 18 days set during the period of August 23 

through September 9, 2003, when a total of 3.73" of precipitation fell. 

The most precipitation ever recorded in one calendar year at Flagstaff was 36.59 inches, 

set during 1965. The least precipitation recorded in one calendar year at Flagstaff was 9.90 

inches, set in 1942. Average annual precipitation for Flagstaff is 22.91 inches. 
6 

II. TEMPERATURE RECORDS 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: JANUARY 
7 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 61 1981 17 1919 34 1934 -21 1919

2 60 1902 19 #1919 41 1997 -21 1919 

3 62 1918 17 1949 31 2005 -19 #1937 

4 64 1927 12 1971 33 1991 -22 1971 

5 61 1948 10 1971 33 #1991 -22 1910 

6 61 1969 8 1913 33 1921 -18 1910 

7 65 1914 17 1937 34 1993 -17 1913 

8 62 2002 23 #1937 39 1962 -12 1989 

9 61 1996 22 1937 34 2005 -9 1937 

10 65 1990 21 1937 35 2005 -15 1937 

 

11 63 1990 25 1913 36 1982 -23 1913 

12 59 2002 5 1963 35 #1981 -20 1963 

13 59 #2000 19 2007 38 1957 -6 #1963 

14 65 1943 23 2007 35 1909 -15 2007 

15 65 1943 19 2007 35 1938 -12 1937 

16 60 #1974 21 1987 36 1976 -8 1915 

17 62 1971 21 1960 35 1914 -13 1987 

18 64 1971 22 1943 35 1914 -8 1995 

19 62 1986 22 1937 32 #1998 -13 1943 

20 61 1950 16 #1937 34 #1969 -14 1922 

 

21 60 1944 15 1937 35 1969 -24 1937 

22 62 1970 12 1937 31 #1969 -30 1937 

23 61 1970 17 1932 31 1923 -15 #1937 

24 61 1982 15 1937 42 1999 -15 1964 

25 61 1975 24 1937 44 1999 -17 1937 

26 60 1987 22 #1979 37 1969 -15 1937 

27 61 2003 21 1948 34 #1975 -13 1979 

28 63 1986 20 1979 34 1911 -13 1918 

29 60 1986 15 1979 36 1911 -12 1932 

30 66 1971 24 1916 33 1963 -19 1979 

31 63 1971 19 1916 34 #1963 -25 1916 

 

Month 66 1971 5 1963 44 1999 -30 1937 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: FEBRUARY 
8 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 60 #2003 17 1917 40 1963 -23 1985

2 62 1976 17 1985 37 1935 -14 1922 

3 64 1953 20 1933 34 1928 -22 1922 

4 64 1963 23 #1955 34 #1931 -16 1955 

5 67 1963 21 1899 34 1907 -21 1985 

6 65 1963 7 1989 33 1978 -21 1899 

7 66 1963 14 1933 36 1932 -18 #1903 

8 65 1996 22 1929 36 1957 -17 1933 

9 64 1996 20 1939 37 1922 -21 1929 

10 65 1951 21 #1965 35 1922 -17 1933 

 

11 62 1971 21 1965 35 #1971 -12 1908 

12 58 #2002 21 1905 32 #2005 -16 1965 

13 68 1977 22 1949 36 2003 -18 1905 

14 64 1957 25 1942 35 1977 -15 1949 

15 65 #1996 25 1990 33 1941 -10 1942 

16 70 1977 21 1910 35 1904 -3 #1990 

17 66 #1996 27 1917 34 1986 -8 1956 

18 65 1977 24 1917 36 #2005 -11 1942 

19 65 1981 25 1918 38 1986 -6 1942 

20 65 1977 18 1955 41 1996 -11 1955 

 

21 60 #1995 23 1913 43 1996 -9 1955 

22 64 2002 25 1913 41 1901 -10 1955 

23 66 #1946 24 1969 40 1918 -6 1960 

24 66 1904 27 #1987 42 1904 -4 1909 

25 70 1986 27 1987 41 1904 -10 1919 

26 71 1986 25 1962 36 1989 -7 1977 

27 64 1921 25 #1996 36 1904 -12 1962 

28 65 1999 29 #2004 40 1938 -16 1962 

29 59 1984 32 1916 33 1908 -3 1996 

 

Month 71 1986 7 1989 43 1996 -23 1985 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: MARCH 
9 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 66 1921 21 1971 37 1920 -10 1997

2 65 1910 24 1951 36 1974 -1 1971 

3 66 1910 24 1966 39 1967 -9 1915 

4 68 1910 23 1969 35 1995 -16 1966 

5 68 1910 32 #1976 37 #1995 -5 1948 

6 68 1910 29 1969 36 1918 -2 1935 

7 66 #1972 26 1969 38 2002 -1 1945 

8 67 1989 28 1969 32 #1975 -4 #1969 

9 70 1989 30 #1969 40 1943 0 1964 

10 70 1989 25 #1969 40 1985 -9 1958 

 

11 69 1900 25 2006 40 1918 -5 1948 

12 72 1900 25 1956 38 1938 -1 1917 

13 70 2007 27 1962 40 1989 -9 #1962 

14 69 2007 25 1969 39 1984 -4 1990 

15 72 2007 29 1917 35 1943 -3 1962 

16 72 2007 31 2002 39 1914 -1 #1969 

17 73 2007 33 1963 37 1996 3 1991 

18 68 #2004 32 1924 33 1974 -1 1954 

19 71 1907 31 #1982 36 1912 1 1963 

20 72 2004 30 1955 38 1904 -1 1935 

 

21 70 #2004 28 2000 42 1916 5 1948 

22 68 2004 28 1952 37 1929 -1 1952 

23 67 1990 30 #1936 36 2002 -1 1973 

24 70 1956 28 #1929 37 1943 0 1904 

25 72 1988 24 1913 39 1899 1 1913 

26 73 1988 32 1950 37 1971 -8 1902 

27 70 1986 21 1975 39 #1967 -1 1975 

28 68 #1971 26 1975 39 1967 -7 1975 

29 70 1934 27 1998 38 #2002 10 1944 

30 70 1971 33 1998 39 1903 1 1998 

31 73 1966 35 1949 41 1903 3 1912 

 

Month 73 #2007 21 #1975 42 1916 -16 1966 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: APRIL 
10 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 73 1966 31 1999 40 1986 2 1970

2 72 #1966 29 1999 42 2001 -2 1975 

3 71 #1961 30 1999 40 2001 8 1980 

4 74 1961 27 1999 39 1909 5 1977 

5 75 1959 30 1921 40 1919 8 1958 

6 75 1989 34 1929 40 1946 4 1922 

7 80 1989 28 1975 40 1931 10 1922 

8 78 1989 30 1975 41 #2007 14 #1999 

9 75 1989 32 1943 40 1962 9 1953 

10 74 1989 31 #1979 42 1948 13 1999 

 

11 75 1907 29 1927 47 1989 10 1945 

12 75 1904 28 1967 44 1982 7 1953 

13 75 1962 36 1912 40 1988 0 1965 

14 75 1937 33 1938 42 1904 5 1972 

15 76 #1948 33 1998 43 2002 11 1965 

16 77 1948 30 1976 43 #1937 13 1995 

17 77 1946 33 #1995 43 1964 16 1924 

18 79 1989 32 1995 46 1981 16 1978 

19 77 1989 29 1933 51 2001 10 1917 

20 78 1989 33 1995 45 1925 8 1966 

 

21 78 1989 34 1932 44 1989 12 1972 

22 76 1949 30 1925 46 1930 11 1963 

23 77 1949 36 1925 44 1981 14 1963 

24 77 1949 41 2005 47 1943 10 1900 

25 78 1996 38 1994 45 1959 13 #1961 

26 79 1996 34 #1985 45 1917 17 #1984 

27 77 #2000 37 1932 44 1946 10 1984 

28 80 1992 30 1970 49 1981 13 1970 

29 78 1992 35 1942 51 1981 7 1970 

30 78 #1981 34 1915 48 1995 10 1967 

 

Month 80 #1992 27 1999 51 #2001 -2 1975 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: MAY 
11 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 80 1947 27 1915 44 1981 17 #1972

2 84 1947 33 1915 46 1928 13 1915 

3 88 1947 37 1905 46 2007 7 1915 

4 88 1947 38 1905 44 #1947 18 #1915 

5 86 1947 38 #1975 45 1992 18 1950 

6 82 1947 38 1995 48 2000 14 1975 

7 81 1989 38 #1964 44 #1934 15 1938 

8 85 1989 36 1930 48 1934 17 1965 

9 81 1934 38 1922 46 #1989 14 1930 

10 82 1934 34 1922 53 2000 19 1953 

 

11 86 1996 39 1933 47 1992 16 1933 

12 86 1996 43 #1982 50 1934 20 #1983 

13 82 1984 42 1998 48 #1999 18 1953 

14 83 1938 41 1977 47 2003 21 #1942 

15 81 1937 45 #1957 50 1938 20 1968 

16 80 1970 46 #1953 51 1996 16 1955 

17 82 1970 46 1962 48 1974 20 1943 

18 82 1970 46 1921 47 1976 21 1977 

19 81 1920 37 1902 56 1996 20 1971 

20 81 1920 44 1917 52 1901 18 1899 

 

21 82 2005 42 1975 46 #1953 21 1974 

22 85 1984 51 1975 46 #2005 21 1972 

23 85 #2000 51 1957 47 1929 23 1927 

24 83 #1983 41 1965 47 #2000 23 1909 

25 84 1951 47 1965 54 1951 18 1980 

26 87 1951 52 1917 53 1942 19 1916 

27 87 1974 51 1929 50 2006 23 1916 

28 86 #2000 51 1953 51 1925 24 1929 

29 86 #2000 39 1971 50 1928 22 1918 

30 88 2002 49 1988 51 #1939 18 1918 

31 89 2002 49 1917 51 #2003 23 1988 

 

Month 89 2002 27 1915 56 1996 7 1915 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: JUNE 
12 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 88 1977 48 1991 52 2002 24 1923

2 86 1977 44 1899 54 1910 22 1955 

3 86 #1996 53 #1925 51 1960 23 1971 

4 89 1990 46 1915 53 2006 23 1908 

5 87 #2006 56 1932 53 2006 25 1943 

6 87 2002 54 1934 53 2006 28 #1971 

7 89 1985 58 #1941 54 2006 24 1954 

8 89 1985 49 1907 55 1981 24 1950 

9 88 1902 55 1965 53 #1990 24 1950 

10 87 1910 49 1957 61 1978 28 #1998 

 

11 90 1918 57 1928 57 1911 26 1954 

12 91 1918 49 1927 53 1906 27 #1976 

13 92 1974 50 1955 57 1959 30 #1976 

14 92 1974 60 1901 57 2006 25 2001 

15 92 1974 57 1997 55 #1961 28 #2001 

16 92 1940 56 1995 54 1918 24 1907 

17 92 1940 54 1995 47 1949 23 1923 

18 92 1940 60 #1979 54 #1988 24 1995 

19 92 1936 64 #1975 54 1961 25 1979 

20 92 #1936 60 1923 57 1922 30 1979 

 

21 93 1936 53 1947 57 1918 28 1975 

22 94 1954 66 1912 59 #1971 31 1947 

23 93 1974 66 2000 59 1958 31 1948 

24 94 1974 66 1934 60 1994 32 1975 

25 95 1970 68 #1969 64 1902 30 1965 

26 96 1970 63 1965 58 1981 26 1975 

27 94 1974 63 1906 62 1980 26 1965 

28 94 1990 58 1988 60 1931 30 #1965 

29 93 #1990 69 1938 61 1961 30 1913 

30 92 #1994 69 1911 65 1990 31 1913 

 

Month 96 1970 44 1899 65 1990 22 1955 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: JULY 
13 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 91 #1990 58 1911 67 2002 33 2004

2 92 1969 72 #1938 68 2002 34 1997 

3 93 2007 62 1912 61 1973 34 1997 

4 96 2007 66 1912 60 1953 32 1912 

5 97 1973 66 1952 60 1957 32 #1955 

6 96 1989 66 1968 62 1996 35 #1978 

7 92 1905 66 1982 64 1951 32 1955 

8 92 #2002 66 1950 62 1951 32 1955 

9 94 2003 68 1914 60 1985 34 1926 

10 94 2003 66 1930 59 1996 37 1926 

 

11 92 #2003 66 #1999 62 1958 40 1979 

12 94 2002 62 1918 62 1940 39 1952 

13 94 1972 67 1912 65 1935 35 1904 

14 92 1902 64 1910 61 #2002 38 #1962 

15 92 1970 67 1919 60 #2003 38 1905 

16 92 #1961 70 1919 62 #1961 37 2001 

17 91 #1980 64 1902 62 1988 40 1904 

18 93 #2005 68 1919 60 #1936 42 #1940 

19 92 1989 68 1994 60 1925 34 1987 

20 91 1939 68 #1991 63 1901 42 1940 

 

21 92 1937 61 1986 62 1964 38 1924 

22 92 1996 65 1913 63 1996 38 1995 

23 92 #1996 66 1915 66 1949 37 1987 

24 91 #1937 64 1955 59 #2002 39 1995 

25 92 1931 62 1955 61 1929 41 1913 

26 92 1935 65 1912 61 1943 40 1913 

27 93 1947 68 1912 61 2003 36 1913 

28 94 1995 64 1987 60 #2006 36 1913 

29 92 2002 64 1905 61 1947 37 1913 

30 92 1943 66 1921 60 #1963 40 1913 

31 91 #1977 67 1921 61 1901 43 1997 

 

Month 97 1973 58 1911 68 2002 32 #1955 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: AUGUST 
14 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 92 1977 60 1919 60 #1980 42 #1915

2 93 1902 65 1964 63 2000 43 1976 

3 91 1994 66 1907 61 1980 37 1956 

4 91 1994 66 2006 61 1901 35 1956 

5 90 1944 68 1931 65 1903 35 1976 

6 90 #1983 70 #2002 57 #1981 36 1953 

7 92 1978 70 1909 62 1903 39 1991 

8 90 1980 67 1930 60 1965 39 1950 

9 89 1980 64 1918 58 #1970 44 #1999 

10 89 2002 66 1981 59 1940 40 1900 

 

11 91 #1980 65 1918 57 #2006 36 1900 

12 92 1944 62 1979 60 2002 36 1999 

13 90 2002 66 1916 60 1980 39 1999 

14 89 2002 63 #1999 61 1901 33 1976 

15 88 #1962 61 1961 59 1980 33 1968 

16 89 1939 65 1947 58 1963 37 1968 

17 88 2002 67 #1979 57 1945 38 #1979 

18 87 #2002 65 1979 56 #1936 36 1975 

19 88 #1973 65 1979 57 #2002 35 1979 

20 88 #1949 67 1920 58 #2002 35 1979 

 

21 90 1991 64 1921 62 1928 33 1979 

22 88 1938 58 1992 60 1928 32 1968 

23 90 1985 53 1992 58 1982 24 1968 

24 91 1985 64 1986 57 1944 30 1968 

25 88 1985 65 1923 57 1988 36 2002 

26 88 #1974 64 1972 58 #1939 37 1989 

27 88 1944 62 #1993 57 1937 36 1978 

28 89 #1948 58 1951 56 #1967 33 1920 

29 91 1948 57 1951 56 1928 37 1956 

30 90 1948 63 #1909 57 1929 36 #1975 

31 89 #1950 63 1966 55 #1998 35 1957 

 

Month 93 1902 53 1992 65 1903 24 1968 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: SEPTEMBER 
15 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 91 1948 63 1913 56 1995 33 1962

2 91 1948 64 #1940 55 1936 35 1953 

3 91 1948 62 1961 56 2004 34 #1973 

4 90 1945 63 1936 57 #1998 27 1961 

5 89 1945 59 1939 56 1980 31 1961 

6 87 1977 55 1975 56 1899 33 1985 

7 89 1977 62 #1975 55 1903 35 1970 

8 88 #1977 61 1908 57 1919 33 1935 

9 87 #1977 58 1912 55 #2003 31 #2001 

10 87 #1990 65 1996 56 1939 28 1912 

 

11 88 1990 59 1985 54 1952 30 1986 

12 88 1990 56 1927 54 1914 25 1985 

13 89 1990 56 1927 55 #1970 26 1952 

14 88 #2000 57 1911 57 1938 29 #1988 

15 87 #2000 53 1906 52 #1997 26 1903 

16 88 2000 59 #1996 60 1929 28 1971 

17 88 1956 49 1923 56 1929 27 1903 

18 86 1956 46 1965 54 1942 27 2006 

19 84 #1956 51 1965 53 #1992 25 1971 

20 83 #2000 54 1965 53 1939 23 1971 

 

21 84 1943 57 2004 56 1928 23 1955 

22 83 1949 53 1941 53 2000 20 1912 

23 86 1944 51 1986 56 1931 25 1970 

24 85 1947 41 1986 51 1939 25 1918 

25 85 1947 46 1986 54 1929 24 #1959 

26 84 1899 53 1913 50 1926 22 1934 

27 83 1963 52 #1936 49 #1977 23 1900 

28 82 #1963 51 1945 52 1911 21 1900 

29 82 1978 48 1905 50 1911 22 1902 

30 83 1980 54 1971 51 1944 24 1907 

 

Month 91 #1948 41 1986 60 1929 20 1912 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: OCTOBER 
16 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 85 1980 41 1959 53 1981 23 #1982

2 82 1991 45 1959 49 1951 18 1971 

3 83 1980 46 1908 50 1989 21 1902 

4 83 1947 49 1916 50 1900 15 1908 

5 80 1991 40 1912 48 1925 14 1969 

6 81 1987 42 1912 50 1972 18 1912 

7 80 1965 50 1924 47 1923 21 #1955 

8 80 #1980 41 1939 52 1926 21 1900 

9 81 #1996 41 1961 45 #1988 20 1970 

10 81 1996 44 1960 49 2003 20 1973 

 

11 80 #1965 42 1969 47 1981 19 1920 

12 83 1950 39 1947 46 1987 9 1969 

13 79 1950 41 1920 46 1991 12 1969 

14 78 1991 39 1928 46 1944 18 1975 

15 78 1991 38 1960 43 #1938 19 1966 

16 78 1991 38 1994 44 #1972 13 1984 

17 78 1973 31 1971 44 2004 18 1998 

18 78 1921 33 1908 45 #1972 10 1971 

19 77 #2003 38 #1920 44 1979 6 1971 

20 77 2003 32 1920 43 #1951 4 1949 

 

21 75 #2003 37 #1920 46 1901 5 1949 

22 76 2003 32 1906 43 2001 9 1906 

23 76 2003 38 1920 45 1944 10 1906 

24 79 1959 42 1919 43 1960 9 1975 

25 78 1959 37 1971 42 1951 11 1975 

26 75 1959 30 1996 43 1927 14 1972 

27 74 1995 36 1996 45 1927 10 1970 

28 74 1950 35 1996 46 1981 13 1954 

29 72 #1950 31 #1971 40 1992 9 1971 

30 72 1934 32 1961 42 2003 -2 1971 

31 70 #1999 31 1972 42 2003 7 1935 

 

Month 85 1980 30 1996 53 1981 -2 1971 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: NOVEMBER 
17 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 73 1916 35 1956 41 2003 11 #1943

2 73 1977 32 1946 41 1973 10 1956 

3 74 1977 32 1936 41 #1987 8 1922 

4 73 1975 32 1922 40 2001 -1 1922 

5 70 #1976 35 1925 41 1960 1 1922 

6 72 #1934 34 #1925 41 1960 7 1935 

7 71 1934 33 2000 39 1905 8 1947 

8 74 1973 35 1919 44 1931 8 1918 

9 71 1973 35 1966 42 2002 3 1898 

10 71 1973 33 #2000 41 1991 5 1946 

 

11 73 1973 31 2000 40 1991 7 1950 

12 72 1996 30 1972 42 1983 3 1898 

13 72 1967 22 1916 43 1983 -3 2000 

14 70 1967 30 1985 39 1962 -5 1985 

15 70 #1999 24 1964 37 1965 2 1985 

16 70 1981 21 1958 38 1921 -1 1964 

17 65 1929 22 1958 36 1982 -10 1964 

18 68 1898 25 1969 38 1913 -13 1958 

19 69 1949 22 1994 40 1950 -6 1985 

20 71 1976 22 1979 33 1968 -5 1964 

 

21 70 1950 28 1979 41 1966 -5 1979 

22 68 1903 22 1931 41 1919 -2 1931 

23 69 1954 25 1931 41 1965 -4 1931 

24 68 #1970 20 1931 42 1965 -7 1902 

25 70 1949 24 1931 38 1919 -8 1906 

26 70 1977 26 1918 35 1958 -8 1906 

27 68 1949 25 1976 32 1939 -5 #1984 

28 68 1980 26 #1919 30 #2006 -3 #1905 

29 68 1949 24 1975 34 #1954 -8 1905 

30 66 1995 25 1991 37 1980 -3 1975 

 

Month 74 #1977 20 1931 44 1931 -13 1958 

# Also occurred in other previous years 

DAILY MAXIMUM AND MINIMUM TEMPERATURE EXTREMES 

 SEPTEMBER 1898-JULY 2007 

 MONTH: DECEMBER 
18 

Date 

High 

Max Year 

Low 

Max Year 

High 

Min Year 

Low 

Min Year 

1 63 1926 24 1991 36 #1954 -7 1905

2 62 1946 27 1913 36 1906 -5 #1991 

3 67 1977 27 1913 37 1926 -2 #1968 

4 67 1965 26 1909 37 1926 -4 #1955 

5 67 1989 23 1912 37 1921 -1 #1953 

6 62 1977 19 1960 42 1966 -6 1951 

7 66 1958 10 1978 33 2003 -19 1978 

8 62 #1976 12 1978 35 1957 -23 1978 

9 62 #1977 19 #1951 32 1965 -8 1951 

10 65 1939 23 1898 36 1996 -2 1956 

 

11 68 1950 18 1949 36 1996 -11 1961 

12 64 1921 26 #1972 33 #1937 -16 #1961 

13 66 1921 17 1967 39 1995 -19 1931 

14 66 1946 20 1967 36 1934 -14 #1972 

15 63 1929 22 1971 35 1934 -14 1931 

16 63 1958 21 #1971 38 1957 -18 1971 

17 65 #1980 22 1967 32 1929 -14 1928 

18 65 1901 22 #1924 32 1991 -14 1908 

19 62 1958 22 1924 34 1998 -14 1924 

20 61 1917 21 1951 35 1921 -12 1924 

 

21 61 1969 14 1990 33 1921 -6 1967 

22 64 1901 21 1990 33 1982 -16 1968 

23 63 1901 16 1990 33 #1955 -23 1990 

24 61 1933 17 1974 36 1983 -17 1974 

25 67 1980 20 1987 37 1971 -14 1926 

26 63 1980 19 1916 34 1923 -16 1924 

27 67 1980 18 1916 36 1983 -14 #1926 

28 61 1980 25 #1988 35 #1992 -12 1966 

29 62 1945 22 1966 37 1980 -13 1988 

30 62 1917 21 1966 34 1977 -16 1911 

31 62 1945 18 1918 36 1909 -16 1911 

 

Month 68 1950 10 1978 42 1966 -23 #1990 

# Also occurred in other previous years 

HIGHEST AND LOWEST AVERAGE TEMPERATURES 

BY MONTHS WITH YEAR OF OCCURRENCE 

(SEPTEMBER 1898 - JULY 2007) 
19 

 Normal* Highest Lowest 

Month Monthly Average Year Average Year 

January 29.7 37.2 2003 12.7 1937 

February 32.2 38.2 1947! 19.5 1939 

March 36.6 44.9 1934 26.8 1973 

April 42.9 50.4 1989 36.2 1975 

May 50.8 56.8 1984 44.6 1917! 

June 60.1 66.5 1974 53.0 1965 

July 66.1 70.0 2002 61.1 1912! 

August 64.4 67.5 1944! 59.5 1968 

September 57.8 62.1 1947! 52.3 1912! 

October 47.1 52.5 1988 38.6 1971 

November 36.5 44.9 1949! 29.6 1972 

December 30.2 39.8 1980 21.9 1972 

*Climatological normals from the years 1971-2000. 

! Author Note: Due to the fact that weather stations were often moved, especially in the early 

days of the National Weather Service, some records are more representative than others. Even 

though all temperature and precipitation observations are valid for their particular locations, 

some locations have proven to be more representative of the general surrounding area than 

others. In the Flagstaff climatology, there are two periods of observations which appear to be 

not as representative, due to their locations and siting. 

The first of these periods is from March 15, 1912- October 29, 1919 when the observations were 

taken near the intersection of Sitgreaves and Ellery Streets. This location appears to have been a 

cold location, with numerous record lows occurring here. When compared to other locations in 

Arizona during this same period of time, this unusual cold tendency appears to be due to 

instrument error, or to improper siting. You will note many daily, monthly, and yearly cold 

records occurring during the 1912-1919 period. 

The other period of suspect climate information is during the period from June 1, 1943 - 

January 11, 1950 when the observations were being recorded at the old Flagstaff post office, 

located downtown. Again, due to improper siting of the instruments on the post office roof, the 

temperatures occurring at this location appear to be unnaturally too warm when compared to 

surrounding stations. You will note many daily, monthly, and yearly warm records occurring 

during the 1943-1950 period. 

With time, these biased records will be overwritten by new records, however until that happens, 

data from these two periods of record should be viewed cautiously with respect to their siting. 

HIGHEST AND LOWEST MONTHLY AVERAGE TEMPERATURES 

 (SEPTEMBER 1898 - JULY 2007) 

 Highest Monthly Lowest Monthly 

Average Temperature Average Temperature
20 

Month Normal* Temp Year Temp Year

JANUARY 29.7 37.2 2003 12.7 1937 

37.0 1986 19.7 1949 

36.2 1981 19.8 1932 

35.1 1953 21.0 1913 

34.5 1999 21.3 1922 

FEBRUARY 32.2 38.3 1947 19.5 1939 

38.0 1904 20.5 1933 

37.9 1907 20.7 1919 

37.4 1934 22.0 1903 

37.2 1995 22.5 1955 

MARCH 36.6 44.9 1934 26.8 1973 

42.6 2004 27.3 1969 

41.8 1989 28.1 1962 

41.1 1910 28.6 1952 

41.0 2007# 29.0 1917 

APRIL 42.9 50.4 1989 36.2 1975 

49.1 1992 37.0 1983 

48.5 1981 37.2 1998 

48.4 1946 37.5 1999 

48.0 1949 37.5 1970 

MAY 50.8 56.8 1984 44.6 1917 

55.6 1934 45.0 1953 

55.4 2000 45.2 1915 

55.4 1947 45.3 1908 

55.3 2001 45.4 1930 

JUNE 60.1 66.5 1974 53.0 1965 

66.1 1981 54.2 1907 

64.7 1918 54.7 1923 

64.4 1990 55.0 1998 

64.0 2006 55.1 1995 

*Monthly normals based on climatological normals 1971-2000. 

# has occurred in previous years 

HIGHEST AND LOWEST MONTHLY AVERAGE TEMPERATURES 

 (SEPTEMBER 1898 – JULY 2007) 

 Highest Monthly Lowest Monthly 

Average Temperature Average Temperature
21 

Month Normal* Temp Year Temp Year

JULY 66.1 70.0 2002 61.2 1912 

69.5 2003 61.7 1955 

69.4 1901 62.6 1911 

69.0 1980 62.7 1914 

68.7 1931 62.8 1913 

AUGUST 64.4 67.5 1944 59.5 1968 

67.2 1945 60.5 1979 

66.8 1995 60.6 1916 

66.7 1939 60.7 1906 

66.6 1991 60.8 1956 

SEPTEMBER 57.8 62.1 1947 52.3 1912 

61.9 1933 52.8 1900 

61.5 1956 53.0 1986 

60.8 1949 53.0 1971 

60.7 1983 53.1 1985 

OCTOBER 47.1 52.5 1988 38.6 1971 

52.1 1950 40.5 1969 

51.8 2003 41.2 1908 

51.2 1964 42.1 1919 

51.1 1952 42.4 1984 

NOVEMBER 36.5 44.9 1949 29.6 1972 

42.3 1995 30.4 1952 

41.8 1981 30.8 2000 

41.8 1942 31.2 1979 

41.5 1927 31.3 1964 

DECEMBER 30.2 39.9 1980 21.9 1972 

37.6 1977 21.9 1932 

37.0 1939 22.0 1911 

36.5 1958 22.1 1909 

36.4 1981 22.2 1905 

*Monthly normals based on climatological normals 1971-2000. 

WARMEST AND COLDEST 

 WINTER, SPRING, SUMMER, FALL 

 (SEPTEMBER 1898 – JULY 2007) 

 WINTER 

 (DECEMBER 21 - MARCH 20) 

 Average = 31.7* 
22 

 Warmest Coldest

Temp Year Temp Year

37.3 1933-34 22.6 1918-19 

36.9 1980-81 23.3 1916-17 

36.0 1985-86 24.5 1932-33 

35.6 1899-00 24.5 1914-15 

35.1 1998-99 24.8 1936-37 

34.5 1994-95 25.0 1912-13 

34.4 1942-43 25.4 1954-55 

33.9 1999-00 25.7 1948-49 

33.9 1995-96 25.8 1972-73 

33.9 1983-84 26.3 1921-22 

 SPRING 

 (MARCH 21 - JUNE 20) 

 Average = 48.5 * 

 Warmest Coldest

Temp Year Temp Year

52.7 1989 43.4 1998 

51.9 1981 43.7 1975 

51.9 1946 44.3 1965 

51.8 1940 44.3 1917 

51.6 2002 44.5 1995 

51.6 2000 44.7 1967 

51.4 1947 45.2 1980 

51.3 1974 45.2 1972 

51.3 1934 45.3 1983 

51.2 2001 45.3 1979 

*Averages based on climatological normals from 1971-2000. 

WARMEST AND COLDEST 

 WINTER, SPRING, SUMMER, FALL 

 (SEPTEMBER 1898 – JULY 2007) 

 SUMMER 

 (JUNE 21 - SEPTEMBER 20) 

 Average = 63.7* 
23 

 Warmest Coldest

Temp Year Temp Year

66.3 1945 59.3 1912 

66.2 1980 60.8 1906 

65.9 2002 60.9 1916 

65.9 1943 61.1 1904 

65.6 1937 61.2 1911 

65.5 1981 61.2 1907 

65.5 1977 61.3 1965 

65.4 1901 61.3 1915 

65.3 1974 61.5 1950 

65.2 1960 61.6 1968 

 FALL 

 (SEPTEMBER 21 - DECEMBER 20) 

 Average = 40.9* 

 Warmest Coldest

Temp Year Temp Year

45.4 1977 33.3 1971 

45.4 1950 36.0 1972 

45.0 1980 36.7 1908 

44.6 1942 37.5 1961 

44.6 1921 37.8 1931 

44.5 1981 37.8 1919 

44.3 1937 38.0 1912 

44.1 1939 38.3 1951 

43.9 1995 38.3 1905 

43.9 1910 38.3 1902 

*Averages based on climatological normals 1971-2000 

HIGHEST AND LOWEST ANNUAL TEMPERATURE 

 (1899-2006) 

Highest Annual Average Lowest Annual Average

Temp Year Temp Year
24 

49.5 1981 43.0 1915! 

48.9 1934 43.0 1913! 

48.1 1943! 43.4 1912! 

48.1 1940 43.5 1979 

47.9 2003 43.7 1971 

47.9 1946! 43.8 1919! 

47.8 1989 43.9 1908 

47.7 1977 44.0 1972 

47.6 2000 44.0 1955 

47.6 1947! 44.0 1917! 

 Average Annual 

 Temperature* 

 46.2 

* Averages based on climatological normals 1971-2000. 

! These years should be viewed with caution due to suspect observations due to siting issues. 

AVERAGE NUMBER OF DAYS PER YEAR WITH MAXIMUM TEMPERATURES 

 80, 85, AND 90 DEGREES OR HIGHER 

 (1971-2000) 

 80 Degrees or higher.................61 days 

 85 Degrees or higher.................25 days 

 90 Degrees or higher...................4 days 
25 

AVERAGE NUMBER OF DAYS PER YEAR WITH MINIMUM TEMPERATURES 

 40, 32, AND 0 DEGREES OR LOWER 

 (1971-2000) 

 40 Degrees or lower................265 days 

 32 Degrees or lower................206 days 

 0 degrees or lower.......................6 days 

FREEZE AND GROWING SEASON DATA 

 (1950-2006) 

 The longest growing season on record..........................145 days in 1981* 

 The shortest growing season on record...........................72 days in 1968* 

 Average growing season..............................................................103 days 

 Average date of the last spring frost (32 degrees).........................June 10 

 Earliest date of the last spring frost (32 degrees)................May 12, 2003 

 Latest date of the last spring frost (32 degrees).....................July 8, 1955 

 Average date of the first fall frost (32 degrees)...................September 21 

 Earliest date of the first fall frost (32 degrees)....................Aug 22, 1968 

 Latest date of the first fall frost (32 degrees) .......................Oct 14, 1981 

 Average date of the last spring freeze (28 degrees)....................May 28 

 Earliest date of the last spring freeze (28 degrees)...............Apr 23, 1992 

 Latest date of the last spring freeze (28 degrees)................June 27, 1965 

 Average date of the first fall freeze (28 degrees).....................October 5 

 Earliest date of the first fall freeze (28 degrees)..................Aug 23, 1968 

 Latest date of the first fall freeze (28 degrees)......................Oct 26, 1991 

* Based on the last day of 32 degrees in the spring and the first days of 32 degrees in the fall. 

GREATEST NUMBER OF CONSECUTIVE DAYS WITH 

 MAXIMUM TEMPERATURES 

 85 DEGREES OR HIGHER 

 (SEPTEMBER 1898 - JULY 2007) 

Days Date 

22 June 10 - July 1, 1974 

20 July 17 - Aug 5, 2000 

15 July 3 – July 17, 2003 

15 July 24 - Aug 7, 1995 

15 July 5 - July 19, 1901 
26 

14 June 18 - July 1, 1990 

14 June 24 - July 7, 1973 

13 July 27 - Aug 8, 1978 

13 June 19 - July 1, 1929 

12 June 29 – July 10, 2007 

12 July 6 - July 17, 1948 

12 July 3 - July 14, 1940 

Only periods with 12 or more days are tabulated. 

GREATEST NUMBER OF CONSECUTIVE DAYS WITH 

 MAXIMUM TEMPERATURES 

 90 DEGREES OR HIGHER 

 (SEPTEMBER 1898 - JULY 2007) 

Days Date 

11 June 21 - July 1, 1990 

 6 July 3 - July 8, 1989 

 5 July 1 – July 5, 2007 

 5 July 9 – July 13, 2003 

 5 June 26 - June 30, 1974 

 4 July 12 – July 15, 2005 

 4 July 26 - July 29, 1995 

 4 June 27 - June 30, 1980 

 4 June 21 - June 24, 1974 

 4 June 12 - June 15, 1974 

 4 July 2 - July 5, 1973 

 4 July 12 - July 15, 1972 

 4 June 24 - June 27, 1970 

 4 July 14 - July 17, 1948 

 4 July 26 - July 29, 1947 

 4 July 30 - Aug 2, 1938 

 4 July 23 - July 26, 1931 

 4 June 20 - June 23, 1929 

Only periods with 4 or more days are tabulated. 

GREATEST NUMBER OF CONSECUTIVE DAYS WITH 

 MINIMUM TEMPERATURES 

 32 DEGREES OR LOWER 

 (SEPTEMBER 1898 - JULY 2007) 

Days Date 

 192 Oct 19, 1972 – Apr 28, 1973 

 176 Nov 10, 1969 – May 4, 1970 

 167 Oct 29, 1967 – Apr 12, 1967 

 161 Oct 30, 1948 – Apr 8, 1949 

 157 Nov 8, 1987 – Apr 12, 1988 

 143 Nov 19, 1986 – Apr 10, 1987 
27 

 142 Oct 21, 1932 – Mar 10, 1933 

 141 Nov 4, 1952 – Mar 24, 1953 

 140 Nov 14, 1960 – Apr 2, 1961 

 140 Nov 16, 1918 – Apr 4, 1919 

Only periods with 140 or more days are tabulated. 

GREATEST NUMBER OF CONSECUTIVE DAYS WITH 

 MINIMUM TEMPERATURES 

 0 DEGREES OR LOWER 

 (SEPTEMBER 1898 – JULY 2007) 

Days Date 

 8 Dec 27,1966 - Jan 3, 1967 

 8 Dec 31, 1918 - Jan 7, 1919 

 7 Dec 15, 1928 - Dec 21, 1928 

 7 Dec 23, 1926 - Dec 29, 1926 

 6 Dec 22, 1990 - Dec 27, 1990 

 6 Jan 3, 1971 - Jan 8, 1971 

 6 Jan 11, 1963 - Jan 16, 1963 

 6 Jan 1, 1960 - Jan 6, 1960 

 6 Jan 21, 1937 - Jan 26, 1937 

 6 Dec 16, 1932 - Dec 21, 1932 

 6 Dec 30, 1911 - Jan 4, 1912 

 6 Dec 24, 1909 - Dec 29, 1909 

 6 Feb 4, 1903 - Feb 9, 1903 

Only periods with 6 or more days are tabulated. 
28 

III. PRECIPITATION RECORDS 

GREATEST DAILY 24-HOUR PRECIPITATION (INCHES) 

 (Midnight - Midnight) 

 SEPTEMBER 1898 - JULY 2007 

 JANUARY FEBRUARY MARCH APRIL 

Date 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

1 2.08 1910 1.01 1919 2.81 1970 2.95 1903

2 1.45 1922 2.30 1901 0.95 1978 0.91 1977 

3 1.23 2005 1.35 1901 2.11 1938 1.02 1965 

4 1.57 2005 1.44 1958 1.14 1908 1.19 1929 

5 1.15 1974 2.29 1976 0.77 1907 0.80 2001 
29 

Date 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

6 1.23 1965 1.59 1965 0.85 2000 0.41 2002

7 1.42 1993 1.24 1901 0.52 1918 0.62 1946 

8 1.65 1993 2.05 1993 1.27 1918 1.04 1935 

9 1.13 1905 2.07 1976 0.70 1926 0.62 1965 

10 1.61 1911 1.63 1978 1.85 1912 0.71 1965 

 

11 0.97 2005 1.36 2005 1.91 1982 1.09 1905 

12 1.00 2001 0.70 1931 1.43 1906 1.67 1941 

13 1.12 1997 1.84 1992 1.27 1905 0.65 1976 

14 0.42 1969 2.37 1980 1.31 1944 0.71 1976 

15 0.92 1978 1.07 1927 0.77 1945 0.48 1976 

16 0.84 1917 1.40 1927 1.27 1930 1.80 1934 

17 1.83 1979 0.49 1971 0.73 1922 1.67 1917 

18 1.73 1952 0.65 1980 0.64 1982 0.72 1968 

19 0.74 1937 3.93 1993 1.58 1994 0.44 1951 

20 0.90 1917 1.18 1993 0.69 1981 0.56 1995 

 

21 1.36 1982 1.03 1944 1.02 1991 1.70 1985 

22 1.53 1909 0.68 1907 1.28 1954 1.08 1925 

23 1.73 1943 0.62 1957 1.09 1954 0.45 !1999 

24 1.11 1944 1.19 1987 1.14 1902 1.01 1990 

25 1.70 1901 0.84 1958 1.83 1910 0.36 1994 

26 0.84 1997 1.17 1902 1.10 1989 1.22 1963 

27 1.81 1916 0.80 1905 0.59 1938 0.69 1994 

28 0.85 1916 1.80 1991 1.13 1998 1.01 1900 

29 2.05 1915 0.73 1960 0.83 1967 0.74 1951 

30 1.21 1922 0.84 1970 0.78 1954 

31 0.87 1919 1.24 1903 

 

Month 2.08 1910 3.93 1993 2.81 1970 2.95 1903 

! Also occurred in other years 

GREATEST DAILY 24-HOUR PRECIPITATION (INCHES) 

 (Midnight - Midnight) 

 SEPTEMBER 1898 – JULY 2007 

 MAY JUNE JULY AUGUST 

Date 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

1 0.77 1915 0.31 1991 0.51 1911 1.38 1906

2 0.75 1901 0.91 1999 1.39 1919 1.71 1963 
30 

Date 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

3 0.97 1908 0.31 1915 0.92 !1944 1.64 1907

4 0.67 1960 0.52 1986 1.85 1986 1.11 1993 

5 0.55 1992 0.40 1903 1.06 1967 0.76 2000 

6 0.93 1921 0.55 1993 0.55 1990 2.16 1986 

7 0.33 1927 0.28 !1912 0.77 1974 1.14 1937 

8 0.77 1976 0.34 1907 1.33 1981 1.38 1959 

9 0.85 1922 0.26 1983 0.88 1988 1.40 1977 

10 0.63 1944 1.47 1957 0.76 1919 1.30 1953 

 

11 0.81 1980 0.39 1927 1.03 1918 1.10 1979 

12 0.45 1965 1.32 1955 0.69 1918 1.99 1987 

13 0.53 1994 1.58 1955 1.55 1976 3.04 1986 

14 0.72 1901 0.88 1921 0.84 1967 1.10 1909 

15 0.52 1951 0.09 1965 2.55 1964 1.10 1921 

16 0.30 1951 0.17 1933 1.05 1908 0.85 1958 

17 0.96 1903 0.70 1933 1.08 1911 1.28 1920 

18 0.45 1915 0.89 1949 0.93 1946 1.07 1989 

19 0.50 1957 0.45 1967 2.14 1986 0.90 1984 

20 0.95 1900 0.32 1925 1.59 1986 1.84 2004 

 

21 0.52 1975 0.68 1958 1.20 1918 1.88 1932 

22 0.31 1919 1.27 1922 1.51 1962 2.75 1992 

23 0.97 1919 0.17 2000 1.35 1983 1.62 1988 

24 1.11 1965 0.29 1922 1.37 1984 1.13 2005 

25 0.23 1994 0.78 1954 1.35 2003 1.10 1931 

26 0.75 1992 0.32 1954 1.61 1969 0.98 1984 

27 0.68 1901 0.75 1940 1.13 1905 0.82 1985 

28 0.61 1990 0.66 1938 2.19 1929 2.28 1951 

29 0.92 1992 2.40 1956 1.37 1977 1.62 1951 

30 0.46 1986 0.39 1956 1.21 1964 1.23 1946 

31 0.39 2003 1.14 2005 1.79 1963 

 

Month 1.11 1965 2.40 1956 2.55 1964 3.04 1986 

! Also occurred in previous years. 

GREATEST DAILY 24-HOUR PRECIPITATION (INCHES) 

 (Midnight - Midnight) 

 SEPTEMBER 1898 - JULY 2007 

 SEPTEMBER OCTOBER NOVEMBER DECEMBER 
31 

Date 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

24 Hr 

Pcpn Year 

1 1.32 1998 0.85 1959 1.53 1987 0.45 1955

2 0.86 1990 1.03 1981 1.30 1957 0.94 1906 

3 0.59 1907 1.34 1968 1.46 1957 1.33 1908 

4 0.65 1970 1.60 1972 0.48 1925 1.55 1992 

5 2.84 1970 1.80 1940 0.71 1987 0.98 1966 

6 0.82 2002 2.34 1993 0.95 1915 2.87 1966 

7 1.08 2002 1.55 1924 0.76 1969 0.94 1966 

8 0.87 1990 1.36 1961 1.80 1966 0.83 1972 

9 1.61 2003 1.13 1960 0.87 1915 1.10 1965 

10 1.40 1924 0.58 1985 1.90 1923 0.97 1961 

 

11 1.97 1985 1.52 1899 3.21 1978 0.98 1927 

12 1.80 1927 1.10 1899 2.00 2003 0.88 1937 

13 2.75 1941 1.31 1941 0.75 1910 1.52 1967 

14 1.50 1999 0.76 2006 1.96 1991 1.41 1967 

15 0.46 1906 0.82 1994 1.25 1991 2.08 1908 

16 0.60 1925 1.77 1971 0.71 1969 1.74 1908 

17 1.71 1925 0.97 1907 1.30 1953 1.20 1978 

18 2.11 1965 1.75 1949 0.66 1973 2.65 1978 

19 1.03 2004 1.52 1972 0.49 1940 2.32 1967 

20 1.52 1952 1.18 1979 1.85 1902 1.16 1968 

 

21 0.81 1990 0.94 2004 1.50 2004 1.03 1909 

22 1.03 1958 0.60 2000 0.68 1965 1.50 1965 

23 2.71 1983 0.57 1921 1.64 1906 1.38 1945 

24 1.65 1900 2.42 1992 0.55 1918 0.44 1959 

25 1.00 1986 1.48 1998 2.00 1985 1.31 1940 

26 1.35 1997 0.67 1982 1.85 1919 1.83 1971 

27 1.56 1903 0.82 1991 2.96 1919 1.22 1984 

28 1.79 1958 1.61 2004 1.86 1975 2.50 1992 

29 1.70 1971 1.24 1987 1.42 1985 3.33 2004 

30 1.75 1983 1.54 1920 2.13 1982 2.95 1951 

31 1.79 1987 1.22 1915 

 

Month 2.84 1970 2.42 1992 3.21 1978 3.33 2004 

MAXIMUM AND MINIMUM PRECIPITATION BY MONTHS 

 WITH YEAR OF OCCURRENCE 

 (SEPTEMBER 1898 - JULY 2007) 

Maximum Monthly Minimum Monthly 
32 

 Precipitation Precipitation

Normal* Amount Year Amount Year

JANUARY 2.18" 9.55" 1993 0.00" 1972 

8.16" 1916 0.02" 2002 

7.21" 1949 0.02" 1912 

6.58" 2005 0.08" 1971 

6.52" 1980 0.13" 1925 

FEBRUARY 2.56" 10.05" 1993 Trace 1967 

8.36" 1901 0.02" 1972 

7.81" 1980 0.02" 1912 

5.96" 1976 0.07" 2002 

5.79 1905 0.08" 1924 

MARCH 2.62" 6.75" 1970 Trace 1972 

6.18" 1973 0.03" 1997 

6.05" 1906 0.06" 1933 

6.00" 1991 0.08" 1959 

5.69" 1982 0.12" 1956 

APRIL 1.29" 5.62" 1965 Trace 1991 

4.47" 1917 0.01" 1989 

4.21" 1900 0.06" 1916 

3.85" 1903 0.07" 1996 

3.83" 1988 0.09" 1962 

MAY 0.80" 4.14" 1992 0.00" 2004 

2.40" 1915 0.00” 2002 

2.27" 1901 Trace 1996 

2.16" 1979 Trace 1974 

2.02" 1957 Trace 1970! 

JUNE 0.43" 2.92" 1955 0.00" 2002 

2.79" 1956 0.00" 1998 

2.19" 1949 0.00" 1971 

1.93" 1972 0.00" 1942 

1.88" 1903 0.00" 1917! 

*Climatological Standard Normals 1971-2000. 

! Also occurred in earlier years. 

MAXIMUM AND MINIMUM PRECIPITATION BY MONTHS 

 WITH YEAR OF OCCURRENCE 

 (SEPTEMBER 1898 - JULY 2007) 

Maximum Monthly Minimum Monthly 
33 

 Precipitation Precipitation

Normal* Amount Year Amount Year

JULY 2.40" 7.58" 1919 Trace 1993 

6.62" 1986 0.21" 1997 

6.06" 1930 0.23" 1900 

5.93" 1917 0.30" 2000 

5.53" 1911 0.32" 1963 

AUGUST 2.89" 8.77" 1904 0.26" 1962 

8.06" 1986 0.37" 1924 

6.73" 1909 0.54" 1915 

6.10" 1902 0.58" 1976 

5.80" 1992 0.61" 1912 

SEPTEMBER 2.12" 6.75" 1983 Trace 1992 

6.60" 1958 Trace 1973 

6.18" 1990 Trace 1957 

4.85" 1965 Trace 1955 

4.80" 1986 0.02" 1956 

OCTOBER 1.93" 9.86" 1972 0.00" 1917 

4.90" 1941 0.00" 1902 

4.89" 1899 Trace 1999 

4.64" 1987 Trace 1952 

4.58" 1907 Trace 1950! 

NOVEMBER 1.86" 7.10" 1905 0.00" 1999 

6.75" 1902 0.00" 1932 

6.64" 1985 0.00" 1916 

6.16" 1978 0.00" 1904 

5.50" 1919 0.00" 1903 

DECEMBER 1.83" 7.30" 1967 0.00" 1917 

6.78" 1992 Trace 1999 

6.63" 1965 Trace 1958 

6.17" 1966 0.01" 2005 

5.74" 1908 0.01" 1929 

*Climatological Standard Normals 1971-2000. 

! Also occurred in earlier years. 

WETTEST AND DRIEST 

 WINTER, SPRING, SUMMER, FALL 

 (SEPTEMBER 1898 - JULY 2007) 

 WINTER 

 (DECEMBER 21 - MARCH 20) 
34 

 Average = 7.21" 

 Wettest Driest

Amount Year Amount Year

23.27" 1992-93 0.72" 2001-02 

18.66" 1979-80 1.24" 1998-99 

16.44" 2004-05 1.41" 1933-34 

14.13" 1977-78 1.55" 2005-06 

13.50" 1915-16 1.65" 1899-00 

12.78" 1904-05 1.88" 1966-67 

12.29" 1981-82 1.97" 1995-96 

12.27" 1968-69 1.98" 1983-84 

12.00" 1948-49 1.99" 1952-53 

11.75" 1900-01 2.09" 1903-04 

 SPRING 

 (MARCH 21 - JUNE 20) 

 Average = 3.06" 

 

 Wettest Driest

Amount Year Amount Year

9.75" 1903 0.20" 1996 

8.75" 1965 0.46" 1966 

7.19" 1992 0.63" 1974 

6.49" 1915 0.65" 1918 

5.88" 1900 0.85" 2002 

5.22" 1917 0.93" 1913 

5.11" 1973 1.00" 1942 

5.09" 1998 1.02" 1948 

5.00" 1964 1.02" 1928 

4.99" 1926 1.03" 2007! 

*Averages based on climatological normals from 1971-2000. 

! also occurred in previous years 

WETTEST AND DRIEST 

 WINTER, SPRING, SUMMER, FALL 

 (SEPTEMBER 1898 - JULY 2007) 

 SUMMER 

 (JUNE 21 - SEPTEMBER 20) 

 Average = 7.04" 
35 

 Wettest Driest

Amount Year Amount Year

16.29" 1986 2.28" 1978 

13.81" 1904 2.76" 1944 

11.79" 1998 2.85" 1991 

11.56" 1970 3.12" 1973 

11.48" 1927 3.22" 1957 

11.34" 1990 3.33" 1979 

11.14" 1919 3.51" 1900 

10.32" 1909 3.54" 1926 

10.11" 1951 3.58" 1948 

10.02" 1911 3.80" 1942 

 FALL 

 (SEPTEMBER 21 - DECEMBER 20) 

 Average = 5.60" 

 Wettest Driest

Amount Year Amount Year

14.60" 1972 0.23" 1929 

12.13" 1978 0.45" 1950 

10.70" 1905 0.62" 1904 

10.50" 1919 0.68" 1917 

 9.88" 1987 1.14" 1956 

 9.55" 1967 1.38" 1945 

 9.53" 1985 1.49" 1999 

 9.51" 1966 1.52" 1989 

 9.49" 1983 1.56" 1898 

 9.24" 1982 1.59" 1976 

*Averages based on climatological normals 1971-2000 

FLAGSTAFF ARIZONA YEARLY PRECIPITATION RECORD 

 (1899-2006) 

1899 19.32" 

1900 16.57" 1940 21.22" 1980 29.30" 

1901 21.48" 1941 25.02" 1981 23.37" 

1902 25.86" 1942 9.90 1982 31.09" 
36 

1903 25.05" 1943 17.34" 1983 29.47" 

1904 20.07" 1944 17.50" 1984 20.09" 

1905 34.53" 1945 17.62" 1985 26.67" 

1906 22.70" 1946 21.74" 1986 32.39" 

1907 25.02" 1947 13.14" 1987 23.98" 

1908 25.91" 1948 15.39" 1988 21.68" 

1909 22.75" 1949 26.79" 1989 14.44" 

1910 18.25" 1950 10.76" 1990 25.67" 

1911 26.00" 1951 25.79" 1991 21.83" 

1912 17.69" 1952 20.06" 1992 34.71" 

1913 15.27" 1953 12.81" 1993 35.60" 

1914 17.40" 1954 19.55" 1994 21.95" 

1915 25.54" 1955 17.97" 1995 19.09" 

1916 23.38" 1956 10.37" 1996 11.81" 

1917 18.82" 1957 24.26" 1997 17.84" 

1918 21.29" 1958 21.22" 1998 27.37" 

1919 28.28" 1959 20.42" 1999 15.79" 

1920 19.33" 1960 16.66" 2000 15.40" 

1921 22.93" 1961 18.95" 2001 17.60" 

1922 25.07" 1962 18.11" 2002 12.89” 

1923 21.07" 1963 14.53" 2003 17.91” 

1924 16.74" 1964 19.04" 2004 23.61” 

1925 19.08" 1965 36.59" 2005 24.01” 

1926 16.58" 1966 20.28" 2006 15.59” 

1927 24.03" 1967 22.27" 

1928 14.88" 1968 16.53" 

1929 15.52" 1969 23.31" 

1930 21.24" 1970 24.02" 

1931 20.34" 1971 21.01" 

1932 21.94" 1972 24.67" 

1933 15.60" 1973 19.71" 

1934 14.80" 1974 17.41" 

1935 16.42" 1975 20.10" 

1936 19.30" 1976 20.12" 

1937 19.41" 1977 18.77" 

1938 20.48" 1978 30.72" 

1939 12.91" 1979 19.68" 

 15 WETTEST CALENDAR YEARS 

 (JANUARY 1899 - DECEMBER 2006) 

Rank Amount Year

1 36.59" 1965 

2 35.60" 1993 

3 34.71" 1992 

4 34.53" 1905 
37 

5 32.39" 1986 

6 31.09" 1982 

7 30.72" 1978 

8 29.47" 1983 

9 29.30" 1980 

10 28.28" 1919 

11 27.37" 1998 

12 26.79" 1949 

13 26.67" 1985 

14 26.00" 1911 

15 25.91" 1908 

 15 DRIEST CALENDAR YEARS 

 (JANUARY 1899 - DECEMBER 2006) 

Rank Amount Year

1 9.90" 1942 

2 10.37" 1956 

3 10.76" 1950 

4 11.81" 1996 

5 12.81" 1953 

6 12.89” 2002 

7 12.91" 1939 

8 13.14" 1947 

9 14.44" 1989 

10 14.53" 1963 

11 14.80" 1934 

12 14.88" 1928 

13 15.27" 1913 

14 15.39" 1948 

15 15.40" 2000 

 *AVERAGE ANNUAL PRECIPITATION: 22.91" 

* Based on the 30 year average annual precipitation from 1971-2000. 

NUMBER OF DAYS WITH 0.01 INCH OR MORE AND 0.10 INCH 

 OR MORE BY MONTH AND YEAR OF OCCURRENCE 

 (SEPTEMBER 1898 – JULY 2007) 

0.01 Inch or more 0.10 Inch or more

 Average Greatest Average Greatest 

Month # of Days # of Days Year # of Days # of Days Year

January 7.4 18 1993 4.6 17 1993 

February 7.4 16 2005* 5.0 14 1905 
38 

March 8.0 21 1973 5.2 15 1973 

April 6.0 20 1926 3.5 11 1926 

May 3.9 15 1992 2.0 11 1992 

June 2.9 10 1988 1.4 8 1972 

July 11.6 21 1959 6.6 16 1919 

August 12.4 23 1904 7.2 18 1904 

September 7.0 16 1997 4.0 13 1996 

October 5.1 15 1972 3.2 13 1972 

November 4.8 15 1931 3.1 11 1905 

December 6.6 18 1984 4.2 12 1984 

Annual 83.3! 121 1941 50.2! 73 1905 

NUMBER OF DAYS WITH 0.25 INCH OR MORE AND 0.50 INCH 

 OR MORE BY MONTH AND YEAR OF OCCURRENCE 

 (SEPTEMBER 1898 – JULY 2007) 

0.25 Inch or more 0.50 Inch or more

 Average Greatest Average Greatest 

Month # of Days # of Days Year # of Days # of Days Year

January 2.7 11 1993 1.3 7 1993* 

February 2.9 10 1905 1.2 6 1980* 

March 3.0 9 1992* 1.2 5 1978* 

April 1.9 8 1965 0.7 6 1965 

May 0.9 6 1992 0.4 3 1992* 

June 0.6 4 1903 0.2 2 1988* 

July 3.7 14 1919 1.6 5 1936* 

August 3.8 10 1934* 1.7 6 1909* 

September 2.3 9 1939 1.1 5 1958 

October 2.0 9 1972* 1.1 6 1972 

November 1.9 9 1905 0.9 5 1905 

December 2.5 9 1965 1.0 5 1966* 

Annual 28.3! 47 1905 12.6! 24 1965 

* Also recorded in earlier years. 

! May be different than sum of average number of days due to rounding. 

GREATEST NUMBER OF CONSECUTIVE DAYS WITH 0.01 INCH OR MORE 

 (Periods with 10 or more days tabulated) 

 (SEPTEMBER 1898 - JULY 2007) 

 Total 

Days Period Precipitation

 18 August 23 – September 9, 2003 3.73” 

 17 July 20 - August 5, 1968 3.29" 

 13 July 18 - July 30, 1959 1.85" 

 13 August 23 - September 4, 1925 1.96" 

 12 July 30 - August 10, 2001 3.43" 
39 

 11 February 7 - February 17, 1992 3.69" 

 11 January 19 - January 29, 1969 4.05" 

 11 January 9 - January 19, 1949 4.52" 

 11 July 10 - July 20, 1919 4.32" 

 10 February 13 - February 22, 1980 7.81" 

 10 August 8 - August 17, 1947 3.21" 

 10 December 24, 1941 - January 2, 1942 1.56" 

 10 April 26 - May 5, 1926 1.36" 

 10 July 17 - July 26, 1909 1.61" 

 10 July 26 - August 4, 1908 3.30" 

GREATEST NUMBER OF CONSECUTIVE DAYS WITH 0.25 INCH OR MORE 

 (Periods with 4 days or more tabulated) 

 (SEPTEMBER 1898 - JULY 2007) 

 Total 

Days Period Precipitation

 7 December 13 - December 19, 1967 7.06" 

 7 July 10 - July 16, 1919 3.50" 

 6 July 20 - July 25, 1915 4.38" 

 5 February 17 - February 21, 1980 4.36" 

 5 October 31 - November 4, 1957 4.57" 

 5 February 13 - February 17, 1927 3.92" 

 4 August 7 - August 10, 2001 2.13" 

 4 February 27 - March 2, 1978 3.75" 

 4 April 13 - April 16, 1976 2.86" 

 4 October 27 - October 30, 1974 2.76" 

 4 July 28 - July 31, 1968 1.55" 

 4 November 22 - November 25, 1965 4.49" 

 4 April 1 - April 4, 1965 3.11" 

 4 March 22 - March 25, 1954 3.08" 

 4 January 25 - January 28, 1916 3.92" 

 4 July 24 - July 27, 1912 2.30" 

 4 December 14 - December 17, 1908 4.38" 

 GREATEST NUMBER OF CONSECUTIVE DAYS WITH 0.50 INCH OR MORE 

 (Periods with 4 or more days tabulated) 

 (SEPTEMBER 1898 - JULY 2007) 

 Total 

Days Period Precipitation

 4 February 18 - February 21, 1980 4.06" 

 4 January 25 - January 28, 1916 3.92" 

 4 July 22 - July 25, 1915 3.65" 

 4 October 11 - October 14, 1899 4.61" 
40 

GREATEST NUMBER OF CONSECUTIVE DAYS WITH 0.75 INCH OR MORE 

 (Periods with 3 or more days tabulated) 

 (SEPTEMBER 1898 - JULY 2007) 

 Total 

Days Period Precipitation

 3 December 5 - December 7, 1966 4.79" 

 3 January 6 - January 8, 1993 3.89" 

 3 February 28 - March 2, 1978 3.47" 

 3 July 23 - July 25, 1915 3.03" 

 3 March 24 - March 26, 1906 2.62" 

 3 October 11 - October 13, 1899 3.87" 

GREATEST NUMBER OF CONSECUTIVE DAYS WITHOUT MEASURABLE 

PRECIPITATION (Less than 0.01 inch) DURING AN ENTIRE YEAR 

 (SEPTEMBER 1898 - JULY 2007) 

Days Period Days Period

 99 September 24 - December 31, 1999 67 April 27 - July 3, 2002 

 93 April 3 - July 4, 1974 64 February 7 - April 10, 1972 

 77 October 3 - December 18, 1903 63 March 29 - May 30, 1991 

 77 September 10 - November 25, 1898 63 October 26 - December 27, 1989 

 75 April 19 - July 2, 1996 62 May 1 - July 1, 1942 

 69 April 21 - June 28, 1966 61 May 10 - July 9, 1963 

 

EXCESSIVE STORMS* 

 SEPTEMBER 1898 – JULY 2007 

 (tabulated only for storms* with 3.50" or greater total precipitation) 

Days Period Total Precip Highest daily total

 10 February 13 - February 22, 1980 7.80" 2.37" 

 8 December 13 - December 20, 1967 7.20" 2.32" 

 8 February 14 - February 21, 1993 6.48" 3.93" 

 5 December 3 - December 7, 1966 5.50" 2.87" 

 9 January 6 - January 14, 1993 5.40" 1.65" 
41 

 8 February 27 - March 6, 1978 5.12" 1.41" 

 7 October 31 - November 6, 1957 4.76" 1.46" 

 5 October 3 - October 7, 1972 4.70" 1.70" 

 11 January 9 - January 19, 1949 4.51" 1.09" 

 7 July 20 - July 26, 1915 4.48" 1.19" 

 6 January 25 - January 30, 1916 4.32" 1.81" 

 9 August 21 - August 29, 1904 4.32" 1.44" 

 11 July 10 - July 20, 1919 4.29" 0.76" 

 7 February 11 - February 17, 1927 4.20" 1.40" 

 11 January 19 - January 29, 1969 4.07" 1.30" 

 8 September 5 – September 12, 2002 3.90” 1.12” 

 2 December 28 – December 29, 2004 3.88” 3.33” 

 6 October 15 - October 20, 1972 3.78" 1.52" 

 11 February 7 - February 17, 1992 3.74" 1.84" 

 17 July 20 - August 5, 1968 3.74" 0.50" 

 18 August 23 – September 9, 2003 3.73” 1.61” 

 6 March 11 - March 16, 1982 3.66" 1.91" 

 6 February 27 - March 4, 1938 3.60" 2.11" 

 7 January 14 - January 20, 1916 3.50" 1.32" 

* An excessive storm has been defined as a period of time where measurable precipitation falls 

on consecutive days, leading to 3.50 inches or greater accumulation by the time the precipitation 

ends. 

GREATEST DAILY 24-HOUR SNOWFALL (INCHES) 

 (Midnight - Midnight) 

 SEPTEMBER 1898 - JULY 2007 

 JANUARY FEBRUARY MARCH APRIL 

Date 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

1 9.8 1907 13.6 1990 26.0 1970 9.0 1999

2 6.2 1990 24.0 1901 9.5 1964 17.8 1997 

3 13.6 2005 13.5 1901 11.9 1976 10.2 1965 

4 18.8 2005 11.0 2004 11.0 1923 9.8 1999 

5 12.1 1974 19.9 1976 7.0 2004 4.0 1999 
42 

Date 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

6 13.0 1992 15.2 1965 14.3 2000 7.2 2001

7 16.5 1937 12.4 1901 7.6 2000 6.0 1998 

8 9.1 1985 11.0 1939 13.8 1992 7.4 1975 

9 8.8 1980 7.6 1959 8.9 1948 9.9 1965 

10 15.1 1949 15.0 1978 17.5 1969 7.8 1965 

 

11 10.0 1930 8.7 1973 19.3 1952 6.0 1967 

12 8.2 1960 6.1 1959 10.2 2006 12.0 1941 

13 16.4 1997 9.5 1992 7.1 1990 5.4 1976 

14 3.7 1993 16.0 2001 13.0 1944 7.8 1976 

15 8.9 1978 10.0 1932 10.6 1987 5.0 1976 

16 13.0 1928 5.2 1975 17.6 1986 15.0 1917 

17 14.7 1988 4.8 1971 5.8 1963 10.0 1988 

18 13.2 1980 16.0 1917 8.7 1982 9.3 1968 

19 11.0 1935 11.8 1990 9.0 1980 5.0 1966 

20 7.1 1954 8.7 1987 7.8 1981 8.9 1995 

 

21 15.6 1982 10.0 #1944 15.4 1991 11.1 1988 

22 7.5 1964 8.0 1913 12.2 1973 7.5 1988 

23 17.3 1943 6.0 1948 11.4 1964 3.2 1900 

24 19.9 1949 21.1 1987 11.2 1902 4.9 1994 

25 16.0 1923 12.4 1998 12.0 1903 4.1 1994 

26 13.1 1948 6.1 1962 14.9 1991 8.5 1985 

27 16.0 1916 8.4 1951 6.6 1998 8.7 1994 

28 7.2 1979 11.0 1991 11.6 1973 10.1 1900 

29 18.0 1915 6.4 1960 12.8 1998 9.5 1951 

30 9.6 1980 8.9 1970 10.0 1915 

31 12.0 1922 6.9 1970 

 

Month 19.9 1949 24.0 1901 26.0 1970 17.8 1997 

# Occurred in previous years 

GREATEST DAILY 24-HOUR SNOWFALL (INCHES) 

 (Midnight - Midnight) 

 SEPTEMBER 1898 – JULY 2007 

 MAY JUNE JULY AUGUST 

Date 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

1 5.0 1915 

2 7.5 1901 TR 1992 
43 

Date 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

3 9.0 1904 TR 1949

4 3.9 1905 TR #1999 

5 4.6 1969 TR #1999 

6 4.5 1949 TR 

7 2.1 1964 TR 1992 

8 4.7 1979 0.5 1907 

9 0.5 1922 

10 TR #1991 TR 1949 

 

11 0.3 1957 

12 2.0 1968 

13 3.1 1961 

14 0.3 1998 

15 6.0 1951 

16 1.9 1944 

17 9.0 1903 

18 0.2 1903 

19 0.9 1917 

20 0.4 1975 

 

21 4.7 1975 TR 1947 

22 TR 1975 

23 0.3 1906 

24 6.6 1965 

25 TR #1996 

26 TR 1993 

27 0.8 1962 

28 2.0 1962 

29 2.5 1971 

30 TR 1988 

31 TR #1991 

 

Month 9.0 1903 0.5 1907 0.0 ALL 0.0 ALL 

# Occurred during previous years TR = TRACE 

GREATEST DAILY 24-HOUR SNOWFALL (INCHES) 

 (Midnight - Midnight) 

 SEPTEMBER 1898 - JULY 2007 

 SEPTEMBER OCTOBER NOVEMBER DECEMBER 
44 

Date 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

24 Hr 

Snow Year 

1 0.3 1959 1.0 #2000 4.2 1982

2 0.2 1907 8.0 1974 4.5 1947 

3 0.2 1986 6.0 1922 6.1 1961 

4 TR 1946 5.0 1925 14.6 1992 

5 3.6 1912 3.9 1944 8.5 1992 

6 0.7 1912 6.2 1977 11.5 1943 

7 2.0 1946 5.0 1956 

8 5.0 1961 11.2 1966 8.3 1972 

9 2.0 1961 1.8 1947 14.0 1931 

10 TR 1930 6.2 1982 9.6 1961 

 

11 0.6 1997 11.2 1972 9.6 2001 

12 TR 1909 0.2 1947 18.4 1985 14.0 1932 

13 TR 1947 5.0 1961 26.8 1967 

14 0.5 1923 12.8 1993 15.5 1967 

15 4.5 1980 11.8 1991 8.0 1915 

16 5.9 1971 11.5 1958 7.2 1990 

17 6.7 1971 4.7 1972 10.0 1924 

18 TR 1950 5.5 1908 6.5 7.2 #2002 

19 2.0 1965 4.7 1949 5.5 1979 22.7 1967 

20 7.0 1920 20.0 1902 11.2 1968 

 

21 5.5 2004 15.4 1905 19.6 1909 

22 0.8 1941 5.0 #1902 12.7 1965 

23 TR 1989 TR 1941 11.5 1906 9.7 1982 

24 0.9 1986 1.0 1920 15.5 1906 4.0 1914 

25 9.1 1972 8.0 1983 12.0 1916 

26 2.4 1980 6.4 1990 14.1 1979 

27 TR 1982 1.5 1940 23.0 1919 4.7 1946 

28 9.8 2004 14.2 1975 9.2 1936 

29 0.3 1905 6.0 1922 12.1 1985 12.5 1989 

30 9.5 1974 13.4 1982 31.0 1915 

31 9.0 1920 20.0 1915 

 

Month 2.0 1965 9.8 2004 23.0 1919 31.0 1915 

 

# Occurred during previous years TR = TRACE 

MAXIMUM MONTHLY SNOWFALL 

 WITH YEAR OF OCCURRENCE 

 (SEPTEMBER 1898 - JULY 2007) 

Normal* Amount Year
45 

JANUARY 22.4" 104.8" 1949 

 63.4" 1980 

 59.4" 1979 

 56.3” 2005 

 55.7" 1993 

FEBRUARY 20.8" 84.3" 1901 

 45.5" 1990 

 42.1" 1969 

 41.0" 1998 

 40.7" 1987 

MARCH 23.9" 79.4" 1991 

 77.4" 1973 

 67.3" 1970 

 48.4" 2000 

 45.6" 1981 

APRIL 11.8" 58.3" 1965 

 41.8" 1999 

 40.3" 1900 

 34.5" 1917 

 33.1" 1988 

MAY 1.2" 15.0" 1904 

 10.2" 1903 

 10.0" 1908 

 9.0" 1905 

 8.5" 1915 

JUNE 0.0" 0.5" 1907 

 TR 1999 

 TR 1993 

 TR 1992 

 TR 1949! 

* Monthly normals calculated from period 1971-2000. 

! Also occurred in earlier years. 

MAXIMUM MONTHLY SNOWFALL 

 WITH YEAR OF OCCURRENCE 

 (SEPTEMBER 1898 - JULY 2007) 

Normal* Amount Year
46 

JULY 0.0" 0.0" ALL 

AUGUST 0.0" 0.0" ALL 

SEPTEMBER TR 2.0" 1965 

 0.9" 1986 

 0.3" 1905 

 TR 1991 

 TR 1990! 

OCTOBER 3.3" 24.7" 1971 

 19.0" 1920 

 16.6" 1974 

 15.3” 2004 

 11.8" 1972 

NOVEMBER 12.2" 42.6" 1902 

 40.7" 1985 

 39.5" 1991 

 30.3" 1919 

 27.9" 1906 

DECEMBER 13.8" 86.0" 1967 

 66.3" 1915 

 41.7" 1992 

 38.5" 1965 

 30.7" 1909 

* Monthly normals calculated from period 1971-2000. 

! Also occurred in earlier years. 

FIRST AND LAST SNOWFALLS 

 (1899-2006) 

 Average first date for measurable snowfall..........................October 24 

 Average last date for measurable snowfall..................................May 9 

 Average snowfall season length................................................198 days 

 Earliest date of first measurable snowfall................September 19, 1965 

Latest date of last measurable snowfall...............................June 8, 1907 

FLAGSTAFF SEASONAL SNOWFALL* 

 (1899-2007) 

1900 70.0"! 1935 44.1" 1970 95.7" 2005 130.6” 

1901 124.5" 1936 16.0" 1971 56.6" 2006 44.6” 

1902 76.8" 1937 97.6" 1972 50.3" 2007 50.7” 

1903 128.3" 1938 42.0" 1973 210.0" 
47 

1904 41.4" 1939 70.2" 1974 70.0" 

1905 92.2" 1940 48.4" 1975 141.1" 

1906 63.8" 1941 61.5" 1976 131.6" 

1907 86.4" 1942 65.0" 1977 70.2" 

1908 69.2" 1943 64.4" 1978 116.2" 

1909 73.4" 1944 99.5" 1979 145.5" 

1910 82.9" 1945 84.0" 1980 177.1" 

1911 34.3" 1946 51.5" 1981 92.4" 

1912 70.6" 1947 32.4" 1982 122.4" 

1913 65.4" 1948 107.0" 1983 142.6" 

1914 39.6" 1949 167.0" 1984 32.0" 

1915 117.0" 1950 63.3" 1985 136.0" 

1916 129.5" 1951 73.8" 1986 105.4" 

1917 111.1" 1952 105.9" 1987 121.6" 

1918 28.7" 1953 60.0" 1988 104.5" 

1919 69.8" 1954 89.0" 1989 77.7" 

1920 74.7" 1955 67.6" 1990 113.4" 

1921 53.3" 1956 42.7" 1991 127.9" 

1922 96.6" 1957 53.0" 1992 158.9" 

1923 96.7" 1958 71.5" 1993 150.0" 

1924 54.5" 1959 53.8" 1994 109.5" 

1925 49.5" 1960 77.6" 1995 99.1"! 

1926 29.3" 1961 53.9" 1996 28.5"! 

1927 48.7" 1962 128.9" 1997 107.5"! 

1928 39.0" 1963 47.3" 1998 136.7" 

1929 50.0" 1964 89.4" 1999 72.0" 

1930 57.3" 1965 166.7" 2000 74.4" 

1931 18.0" 1966 83.4" 2001 125.1" 

1932 92.9" 1967 63.1" 2002 38.9" 

1933 66.0" 1968 150.4" 2003 54.9” 

1934 11.2" 1969 134.7" 2004 50.9” 

* Snowfall season is the period of July through June ending in the year indicated. 

! Estimated 

15 SNOWIEST SEASONS 

 (JULY 1899 - JUNE 2007) 

Rank Amount Year

1 210.0" 1972-1973 

2 177.1" 1979-1980 

3 167.0" 1948-1949 
48 

4 166.7" 1964-1965 

5 158.9" 1991-1992 

6 150.4" 1967-1968 

7 150.0" 1992-1993 

8 145.5" 1978-1979 

9 142.6" 1982-1983 

10 141.1" 1974-1975 

11 136.7" 1997-1998 

12 136.0" 1984-1985 

13 134.7" 1968-1969 

14 131.6" 1975-1976 

15 130.6" 2004-2005 

15 LEAST SNOWIEST SEASONS 

 (JULY 1899 - JUNE 2007) 

Rank Amount Year

1 11.2" 1933-1934 

2 16.0" 1935-1936 

3 18.0" 1930-1931 

4 28.5" 1995-1996 

5 28.7" 1917-1918 

6 29.3" 1925-1926 

7 32.0" 1983-1984 

8 32.4" 1946-1947 

9 34.3" 1910-1911 

 10 38.9" 2001-2002 

11 39.0" 1927-1928 

12 39.6" 1913-1914 

13 41.4" 1903-1904 

14 42.0" 1937-1938 

15 42.7" 1955-1956 

 *AVERAGE SEASONAL SNOWFALL: 109.4" 

* Based on the 30 year average seasonal snowfall from 1971-2000. 

NUMBER OF DAYS WITH SNOWFALL OF ONE INCH OR MORE 

AND FOUR INCHES OR MORE BY MONTH AND YEAR OF OCCURRENCE 

 (JANUARY 1950 – JULY 2007) 

One Inch or more Four Inches or more

 Average Greatest Average Greatest 

Month # of Days # of Days Year # of Days # of Days Year

January 4.2 16 1993 2.0 7 1955 
49 

February 4.0 11 1993 1.6 5 1990* 

March 4.7 16 1973 2.1 7 1991* 

April 2.4 10 1965 1.1 6 1965 

May 0.4 3 1971 0.1 1 1979* 

June 0.0 0 0.0 0 

July 0.0 0 0.0 0 

August 0.0 0 0.0 0 

September 0.0 1 1965 0.0 0 

October 0.6 6 1971 0.3 3 1971 

November 2.2 5 1993* 0.9 4 1973 

December 3.4 11 1984 1.3 6 1967 

Annual 21.9! 41 1973 9.2! 18 1980 

NUMBER OF DAYS WITH SNOWFALL OF SIX INCHES OR MORE 

AND TEN INCHES OR MORE BY MONTH AND YEAR OF OCCURRENCE 

 (JANUARY 1950 – JULY 2007) 

Six Inches or more Ten Inches or more

 Average Greatest Average Greatest 

Month # of Days # of Days Year # of Days # of Days Year

January 1.1 5 1980* 0.3 2 2005* 

February 0.8 3 1990* 0.3 2 1990* 

March 1.0 4 2000* 0.3 3 1991* 

April 0.6 5 1965 0.1 2 1988 

May 0.0 1 1965* 0.0 0 

June 0.0 0 0.0 0 

July 0.0 0 0.0 0 

August 0.0 0 0.0 0 

September 0.0 0 0.0 0 

October 0.1 1 2004* 0.0 0 

November 0.5 3 1991 0.2 3 1991 

December 0.7 4 1967 0.2 3 1967 

Annual 4.8! 11 1980* 1.4! 7 1991 

* Also recorded in earlier years. 

! May be different than sum of average number of days due to rounding. 

 SNOWIEST CALENDAR DAYS IN FLAGSTAFF 

 (SEPTEMBER 1898 - JULY 2007) 

(Midnight To Midnight) 

Rank Amount Date

1 31.0" Dec 30, 1915 

2 26.8" Dec 13, 1967 

3 26.0" Mar 1, 1970 

4 24.0" Feb 2, 1901 
50 

5 23.0" Nov 27, 1919 

6 22.7" Dec 19, 1967 

7 21.1" Feb 24, 1987 

8 20.0" Dec 31, 1915 

9 20.0" Nov 20, 1902 

10 19.9" Feb 5, 1976 

11 19.9" Jan 24, 1949 

12 19.6" Dec 21, 1909 

13 19.3" Mar 11, 1952 

14 18.8" Jan 4, 2005 

15 18.4" Feb 2, 1988 

SNOWIEST CONSECUTIVE TWO CALENDAR DAYS IN FLAGSTAFF 

(SEPTEMBER 1898 - JULY 2007) 

(tabulated only for events with 25" or greater) 

 

Amount Date

 51.0" December 30 – December 31, 1915 

 42.3" December 13 – December 14, 1967 

 37.5" February 2 – February 3, 1901 

 35.1" January 23 – January 24, 1949 

 34.0" December 29 – December 30, 1915 

 33.0" November 20 – November 21, 1902 

 32.4" January 3 – January 4, 2005 

 32.0" February 1 – February 2, 1901 

 31.9" March 1 – March 2, 1970 

 29.9" December 18 – December 19, 1967 

 29.1" February 28 – March 1, 1991 

 28.1" January 24 – January 25, 1949 

 28.0" January 26 – January 27, 1916 

 27.0" November 23 – November 24, 1906 

 26.7" February 24 – February 25, 1987 

 26.0” November 27 – November 28, 1919 

EXCESSIVE SNOWSTORMS* AT FLAGSTAFF 

 (JANUARY 1899- JULY 2007) 

 (tabulated only for storms* with 25" or greater) 

Days Period Total Snow Highest daily total

 8 December 13 - December 20, 1967 84.6" 26.8" 

 3 December 29 - December 31, 1915 54.0" 31.0" 

 9 January 9 - January 17, 1949 48.4" 15.1" 

 4 February 1 - February 4, 1901 47.4" 24.0" 
51 

 4 January 22 - January 25, 1949 43.5" 19.9" 

 5 April 1 -April 5, 1999 41.3" 11.0" 

 6 January 25 - January 30, 1916 39.0" 16.0" 

 4 November 20 - November 23, 1902 38.6" 20.0" 

 3 January 3 – January 5, 2005 35.0” 18.8” 

 6 February 6 - February 11, 1901 33.6" 12.4" 

 4 February 28 - March 3, 1970 33.3" 26.0" 

 6 April 7 - April 12, 1965 32.6" 9.9" 

 8 December 25 - January 1, 1937 32.2" 10.8" 

 3 February 28 – March 2, 1991 31.5” 18.1” 

 7 March 7 – March 13, 2006 31.2” 14.8” 

 4 February 23 - February 26, 1987 31.2" 21.1" 

 5 January 14 - January 18, 1979 30.7" 14.3" 

 5 April 1 - April 5, 1997 29.7" 17.8" 

 8 January 15 - January 22, 1917 29.7" 12.0" 

 4 April 13 - April 16, 1976 28.7" 10.5" 

 6 March 5 - March 10, 2000 28.3" 14.3" 

 3 April 15 - April 17, 1917 27.5" 15.0" 

 3 November 23 - November 25, 1906 27.2" 15.5" 

 3 January 28 - January 30, 1980 27.1" 15.3" 

 3 February 4 - February 6, 1976 26.9" 19.9" 

 6 January 20 - January 25, 1962 26.7" 13.7" 

 9 December 30 - January 7, 1982 26.6" 9.4" 

 5 January 10 - January 14, 1930 26.5" 10.0" 

 5 March 26 - March 30, 1998 26.4" 12.8" 

 2 November 27 - November 28, 1919 26.0" 23.0" 

 3 January 22 - January 24, 1943 25.9" 17.3" 

 5 April 1 - April 5, 1965 25.7" 10.2" 

 3 November 27 - November 29, 1975 25.2" 14.2" 

* An excessive snowstorm has been defined as a period of time where measurable snowfall 

occurs on consecutive days, leading to 25 inches or greater accumulation by the time the 

snowfall ends. 

AVERAGE NUMBER OF DAYS WITH SNOWFALL OF 1 INCH OR MORE 

 (1950-2006) 

JANUARY 4.2 

FEBRUARY 4.0 

MARCH 4.7 

APRIL 2.4 

MAY 0.4 

JUNE 0 

JULY 0 

AUGUST 0 
52 

SEPTEMBER * 

OCTOBER 0.5 

NOVEMBER 2.1 

DECEMBER 3.2 

ANNUAL 21.5 

 AVERAGE NUMBER OF DAYS WITH THUNDERSTORMS 

 (1965-1994) 

JANUARY * 

FEBRUARY 0.3 

MARCH 0.6 

APRIL 1.3 

MAY 2.6 

JUNE 3.7 

JULY 16.4 

AUGUST 15.6 

SEPTEMBER 6.7 

OCTOBER 2.2 

NOVEMBER 0.6 

DECEMBER 0.2 

ANNUAL 50.1 

* Less than 0.1 occurrences. 
53 

IV. MISCELLANEOUS INFORMATION 

SUNSHINE, CLOUDINESS, AND FOG AT FLAGSTAFF 

 (1965-1994) 

Sunshine Sky Cover (Sunrise - Sunset) Dense Fog

 Percent Avg Amt Number 

 Possible of Sky Partly of 

Month Sunshine Cover Clear Cloudy Cloudy Days
54 

January 77% 5.2 12.4 6.3 12.3 1.8 

February 73% 5.3 10.7 6.0 11.5 1.8 

March 76% 5.3 11.6 7.8 11.6 1.6 

April 82% 4.7 12.4 8.8 8.7 1.2 

May 88% 4.1 15.2 9.3 6.5 0.2 

June 86% 3.0 18.5 7.7 3.9 0 

July 75% 5.3 9.1 13.1 8.8 0.2 

August 76% 5.1 9.8 13.1 8.1 0.3 

September 81% 3.7 15.7 9.6 4.7 0.5 

October 79% 3.6 17.1 7.0 6.9 0.9 

November 75% 4.2 15.4 6.6 8.0 1.2 

December 73% 4.8 13.9 6.5 10.7 1.9 

Annual 78% 4.5 161.8 101.7 101.6 11.5 

Dense fog is defined as surface visibility restrictions of 1/4 mile or less for at least part of the 

day due to obscuration by cloud. Sky cover is expressed in a range from 0 to 10, with 0 

representing no clouds or obscuring phenomena, and 10 representing a complete sky cover. A 

further break-down is as follows: 

 Clear 0/10 to 3/10 sky cover 

 Partly Cloudy 4/10 to 7/10 sky cover 

 Cloudy 8/10 to 10/10 sky cover 

NORMAL HEATING DEGREE DAYS FOR FLAGSTAFF 

 (1971-2000) 

 JANUARY 1099 

 FEBRUARY 930 

 MARCH 880 

 APRIL 668 

 MAY 446 

 JUNE 174 

 JULY 33 

 AUGUST 56 

 SEPTEMBER 224 

 OCTOBER 554 

 NOVEMBER 850 
55 

 DECEMBER 1085 

 ANNUAL 6999 

 NORMAL COOLING DEGREE DAYS FOR FLAGSTAFF 

 (1971-2000) 

 JANUARY 0 

 FEBRUARY 0 

 MARCH 0 

 APRIL 0 

 MAY 0 

 JUNE 23 

 JULY 64 

 AUGUST 36 

 SEPTEMBER 3 

 OCTOBER 0 

 NOVEMBER 0 

 DECEMBER 0 

 ANNUAL 126 

A degree day is a measure of the departure of the average daily temperature from 65 degrees. 

Each degree that the daily temperature is below 65 degrees is equal to one heating degree day. 

Each degree that the daily temperature is above 65 degrees is equal to one cooling degree day. 

For example, if the average temperature on a particular day was 55 degrees, the heating degree 

days would be 10 (65-55). If the average daily temperature was 72 degrees, the cooling degree 

days would then be 7 (72-65). Each day of the month would be calculated in the same fashion, 

with negative differences counted as zero. 

Heating and cooling degree days are useful in the computation of fuel and power consumption 

and are used by utility companies to determine heating and cooling requirements. 

MONSOON STATISTICS 

(1948-2006) 

(Based on Phoenix Official Monsoon Data) 

 Average Starting Date of the Monsoon.................July 7 

 Average Ending Date of the Monsoon.................Sept 13 

 (based on criteria of three consecutive days with average 

dewpoint temperatures in Phoenix of 55 degrees or greater) 

EARLIEST AND LATEST START DATES FOR THE MONSOON SEASON 

 (1948-2007) 

(based on Phoenix Official Monsoon Data) 
56 

 Earliest Start Date Latest Start Date

 June 17, 2000 July 25, 1987 

 June 19, 1958 July 21, 1997 

 June 21, 2001 July 21, 1960 

June 23, 1954 July 19, 2007 

June 25, 1999 July 19, 1980 

June 25, 1984 July 19, 1963 

June 27, 1966 July 18, 2005 

June 27, 1962 July 18, 2003 

June 28, 1959 July 17, 1994 

June 29, 1990! July 17, 1979! 

EARLIEST AND LATEST END DATES FOR THE MONSOON SEASON 

 (1948-2006) 

(based on Phoenix Official Monsoon Data) 

 Earliest End Date Latest End Date

Aug 19, 2004 Oct 10, 1983 

Aug 19, 1979 Oct 10, 1977 

Aug 22, 1973 Oct 8, 1966 

Aug 22, 1962 Oct 5, 1984 

Aug 27, 1956 Sept 28, 1976 

Aug 30, 1957 Sept 28, 1974 

Aug 31, 2000 Sept 26, 1982 

Aug 31, 1953 Sept 25, 1990 

Sept 1, 1948 Sept 24, 1981 

Sept 2, 1988! Sept 24, 1952 

! Also occurred in earlier years. 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

The daily values presented in these tables are not simple means of observed daily values. They 

are interpolated using a much less variable set of monthly normals calculated using the natural 

spline function. 

In leap years, use the February 28th values for the 29th, and adjust the heating degree monthly 
57 

totals accordingly. 

Daily precipitation normals were also computed using the natural spline function and do not 

exhibit the typical daily random fluctuations. However, they may be used to compute normal 

precipitation over time intervals. 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

JANUARY

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 42 16 29 36 0 .06 

 2 42 16 29 36 0 .06 
58 

 3 42 16 29 36 0 .06 

 4 42 16 29 36 0 .06 

 5 42 16 29 36 0 .06 

 6 42 16 29 36 0 .06 

 7 42 16 29 36 0 .06 

 8 42 16 29 36 0 .06 

 9 43 16 29 36 0 .07 

 10 43 16 29 36 0 .07 

 11 43 16 29 36 0 .07 

 12 43 16 29 36 0 .07 

 13 43 16 30 36 0 .07 

 14 43 16 30 36 0 .07 

 15 43 16 30 35 0 .07 

 16 43 16 30 35 0 .07 

 17 43 17 30 35 0 .07 

 18 43 17 30 35 0 .07 

 19 43 17 30 35 0 .07 

 20 43 17 30 35 0 .07 

 21 43 17 30 35 0 .07 

 22 43 17 30 35 0 .07 

 23 43 17 30 35 0 .08 

 24 43 17 30 35 0 .08 

 25 43 17 30 35 0 .08 

 26 43 17 30 35 0 .08 

 27 44 17 30 35 0 .08 

 28 44 17 30 35 0 .08 

 29 44 17 31 35 0 .08 

 30 44 17 31 35 0 .08 

 31 44 17 31 35 0 .08

TOTAL 1099 0 2.18 

AVG 42.9 16.5 29.7 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

FEBRUARY

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 44 17 31 35 0 .08 

 2 44 18 31 35 0 .08 
59 

 3 44 18 31 34 0 .08 

 4 44 18 31 34 0 .09 

 5 44 18 31 34 0 .09 

 6 45 18 31 34 0 .09 

 7 45 18 31 34 0 .09 

 8 45 18 31 34 0 .09 

 9 45 18 32 34 0 .09 

 10 45 18 32 34 0 .09 

 11 45 18 32 34 0 .09 

 12 45 18 32 34 0 .09 

 13 45 19 32 34 0 .09 

 14 46 19 32 33 0 .09 

 15 46 19 32 33 0 .09 

 16 46 19 32 33 0 .09 

 17 46 19 32 33 0 .09 

 18 46 19 33 33 0 .09 

 19 46 19 33 33 0 .09 

 20 46 19 33 33 0 .09 

 21 46 19 33 32 0 .09 

 22 47 20 33 32 0 .10 

 23 47 20 33 32 0 .10 

 24 47 20 33 32 0 .10 

 25 47 20 33 32 0 .10 

 26 47 20 34 32 0 .10 

 27 47 20 34 32 0 .10 

 28 47 20 34 31 0 .10

TOTAL 930 0 2.56 

AVG 45.6 18.8 32.2 

In leap years, use the February 28 values for February 29 and adjust the monthly totals. 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

MARCH

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 47 21 34 31 0 .10 

 2 48 21 34 31 0 .10 
60 

 3 48 21 34 31 0 .10 

 4 48 21 35 31 0 .10 

 5 48 21 35 30 0 .09 

 6 48 21 35 30 0 .09 

 7 48 22 35 30 0 .09 

 8 48 22 35 30 0 .09 

 9 49 22 35 30 0 .09 

 10 49 22 36 29 0 .09 

 11 49 22 36 29 0 .09 

 12 49 22 36 29 0 .09 

 13 49 22 36 29 0 .09 

 14 50 23 36 29 0 .09 

 15 50 23 36 29 0 .09 

 16 50 23 37 28 0 .09 

 17 50 23 37 28 0 .09 

 18 51 23 37 28 0 .08 

 19 51 23 37 28 0 .08 

 20 51 23 37 28 0 .08 

 21 51 23 37 27 0 .08 

 22 51 24 38 27 0 .08 

 23 52 24 38 27 0 .08 

 24 52 24 38 27 0 .08 

 25 52 24 38 27 0 .08 

 26 53 24 38 27 0 .07 

 27 53 24 39 26 0 .07 

 28 53 24 39 26 0 .07 

 29 53 25 39 26 0 .07 

 30 54 25 39 26 0 .07 

 31 54 25 39 26 0 .06

TOTAL 880 0 2.62 

AVG 50.3 22.8 36.6 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

APRIL

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 54 25 40 25 0 .06 

 2 55 25 40 25 0 .06 
61 

 3 55 25 40 25 0 .06 

 4 55 25 40 25 0 .06 

 5 55 25 40 25 0 .06 

 6 56 26 41 24 0 .05 

 7 56 26 41 24 0 .05 

 8 56 26 41 24 0 .05 

 9 57 26 41 24 0 .05 

 10 57 26 42 24 0 .05 

 11 57 26 42 23 0 .05 

 12 57 27 42 23 0 .04 

 13 58 27 42 23 0 .04 

 14 58 27 43 23 0 .04 

 15 58 27 43 22 0 .04 

 16 59 27 43 22 0 .04 

 17 59 27 43 22 0 .04 

 18 59 28 43 22 0 .04 

 19 59 28 44 22 0 .04 

 20 60 28 44 21 0 .04 

 21 60 28 44 21 0 .04 

 22 60 28 44 21 0 .04 

 23 61 29 45 21 0 .04 

 24 61 29 45 20 0 .03 

 25 61 29 45 20 0 .03 

 26 61 29 45 20 0 .03 

 27 62 30 46 20 0 .03 

 28 62 30 46 19 0 .03 

 29 62 30 46 19 0 .03 

 30 62 30 46 19 0 .03

TOTAL 668 0 1.29 

AVG 58.4 27.3 42.9 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

MAY

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 63 31 47 19 0 .03 

 2 63 31 47 18 0 .03 
62 

 3 63 31 47 18 0 .03 

 4 64 31 47 18 0 .03 

 5 64 31 48 18 0 .03 

 6 64 32 48 17 0 .03 

 7 64 32 48 17 0 .03 

 8 65 32 48 17 0 .03 

 9 65 32 49 16 0 .03 

 10 65 33 49 16 0 .03 

 11 66 33 49 16 0 .03 

 12 66 33 50 16 0 .03 

 13 66 33 50 15 0 .03 

 14 67 34 50 15 0 .03 

 15 67 34 50 15 0 .03 

 16 67 34 51 14 0 .03 

 17 68 34 51 14 0 .03 

 18 68 35 51 14 0 .03 

 19 68 35 52 14 0 .03 

 20 69 35 52 13 0 .03 

 21 69 35 52 13 0 .02 

 22 70 35 53 13 0 .02 

 23 70 36 53 12 0 .02 

 24 70 36 53 12 0 .02 

 25 71 36 53 12 0 .02 

 26 71 36 54 11 0 .02 

 27 72 36 54 11 0 .02 

 28 72 37 54 11 0 .02 

 29 73 37 55 11 0 .02 

 30 73 37 55 10 0 .01 

 31 73 37 55 10 0 .01

TOTAL 446 0 0.80 

AVG 67.6 34.0 50.8 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

JUNE

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 74 37 56 10 0 .01 

 2 74 38 56 9 0 .01 
63 

 3 75 38 56 9 0 .01 

 4 75 38 57 9 0 .01 

 5 76 38 57 8 0 .01 

 6 76 39 57 8 0 .01 

 7 76 39 58 8 0 .01 

 8 77 39 58 8 0 .00 

 9 77 39 58 7 0 .00 

 10 78 40 59 7 1 .00 

 11 77 40 59 7 1 .00 

 12 78 40 59 6 1 .01 

 13 78 40 59 6 1 .01 

 14 79 41 60 6 1 .01 

 15 79 41 60 6 1 .01 

 16 79 41 60 5 1 .01 

 17 80 42 61 5 1 .01 

 18 80 42 61 5 1 .01 

 19 80 42 61 5 1 .01 

 20 80 43 61 5 1 .01 

 21 80 43 62 4 1 .02 

 22 81 43 62 4 1 .02 

 23 81 44 62 4 1 .02 

 24 81 44 63 4 1 .02 

 25 81 44 63 4 1 .02 

 26 81 45 63 3 1 .03 

 27 81 45 63 3 1 .03 

 28 82 45 64 3 1 .03 

 29 82 46 64 3 2 .04 

 30 82 46 64 3 2 .04

TOTAL 174 23 0.43 

AVG 78.7 41.4 60.1 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

JULY

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 82 47 64 2 2 .04 

 2 82 47 64 2 2 .05 
64 

 3 82 47 65 2 2 .05 

 4 82 48 65 2 2 .05 

 5 82 48 65 2 2 .06 

 6 82 48 65 2 2 .06 

 7 82 49 65 2 2 .06 

 8 82 49 66 2 2 .06 

 9 82 49 66 1 2 .07 

 10 82 49 66 1 2 .07 

 11 82 50 66 1 2 .07 

 12 83 50 66 1 2 .07 

 13 83 50 66 1 2 .08 

 14 83 50 66 1 2 .08 

 15 83 50 66 1 2 .08 

 16 83 50 66 1 2 .08 

 17 83 51 67 1 2 .08 

 18 82 51 67 1 3 .08 

 19 82 51 67 1 3 .09 

 20 82 51 67 1 2 .09 

 21 82 51 67 1 2 .09 

 22 82 51 67 1 2 .09 

 23 82 51 67 1 2 .09 

 24 82 51 67 0 2 .09 

 25 82 51 67 0 2 .09 

 26 82 51 67 0 2 .09 

 27 82 51 67 0 2 .09 

 28 82 51 67 0 2 .10 

 29 82 51 66 0 2 .10 

 30 82 51 66 1 2 .10 

 31 82 51 66 1 2 .10

TOTAL 33 64 2.40 

AVG 82.2 49.9 66.1 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

AUGUST

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 82 51 66 1 2 .10 

 2 81 51 66 1 2 .10 
65 

 3 81 51 66 1 2 .10 

 4 81 51 66 1 2 .10 

 5 81 51 66 1 2 .10 

 6 81 51 66 1 1 .10 

 7 81 51 66 1 1 .10 

 8 81 50 66 1 1 .10 

 9 81 50 66 1 1 .10 

 10 81 50 65 1 1 .10 

 11 80 50 65 1 1 .10 

 12 80 50 65 1 1 .10 

 13 80 50 65 1 1 .10 

 14 80 50 65 1 1 .09 

 15 80 49 65 1 1 .09 

 16 80 49 65 2 1 .09 

 17 80 49 64 2 1 .09 

 18 80 49 64 2 1 .09 

 19 79 49 64 2 1 .09 

 20 79 49 64 2 1 .09 

 21 79 48 64 2 1 .09 

 22 79 48 64 2 1 .09 

 23 79 48 63 2 1 .09 

 24 79 48 63 3 1 .09 

 25 78 48 63 3 1 .09 

 26 78 47 63 3 1 .09 

 27 78 47 63 3 1 .09 

 28 78 47 62 3 1 .09 

 29 78 47 62 3 1 .08 

 30 78 47 62 3 1 .08 

 31 78 46 62 4 1 .08

TOTAL 56 36 2.89 

AVG 79.7 49.1 64.4 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

SEPTEMBER

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 77 46 62 4 1 .08 

 2 77 46 61 4 1 .08 
66 

 3 77 45 61 4 1 .08 

 4 77 45 61 4 0 .08 

 5 77 45 61 5 0 .08 

 6 76 45 61 5 0 .08 

 7 76 44 60 5 0 .08 

 8 76 44 60 5 0 .08 

 9 76 44 60 6 0 .07 

 10 75 44 60 6 0 .07 

 11 75 43 59 6 0 .07 

 12 75 43 59 6 0 .07 

 13 75 43 59 7 0 .07 

 14 74 42 58 7 0 .07 

 15 74 42 58 7 0 .07 

 16 74 42 58 7 0 .07 

 17 74 41 58 8 0 .07 

 18 73 41 57 8 0 .07 

 19 73 41 57 8 0 .07 

 20 73 40 57 9 0 .07 

 21 72 40 56 9 0 .07 

 22 72 40 56 9 0 .07 

 23 72 39 56 9 0 .07 

 24 72 39 55 10 0 .07 

 25 71 39 55 10 0 .06 

 26 71 38 55 10 0 .06 

 27 71 38 54 11 0 .06 

 28 70 38 54 11 0 .06 

 29 70 37 53 12 0 .06 

 30 69 37 53 12 0 .06

TOTAL 224 3 2.12 

AVG 73.8 41.7 57.8 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

OCTOBER

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 69 36 53 12 0 .07 

 2 69 36 52 13 0 .07 
67 

 3 68 36 52 13 0 .07 

 4 68 35 52 13 0 .07 

 5 68 35 51 14 0 .07 

 6 67 35 51 14 0 .07 

 7 67 34 50 15 0 .07 

 8 66 34 50 15 0 .06 

 9 66 33 50 15 0 .06 

 10 66 33 49 16 0 .06 

 11 65 33 49 16 0 .06 

 12 65 32 49 16 0 .06 

 13 64 32 48 17 0 .06 

 14 64 32 48 17 0 .06 

 15 64 31 47 18 0 .06 

 16 63 31 47 18 0 .06 

 17 63 31 47 18 0 .06 

 18 62 30 46 19 0 .06 

 19 62 30 46 19 0 .06 

 20 62 30 46 19 0 .06 

 21 61 29 45 20 0 .06 

 22 61 29 45 20 0 .06 

 23 60 29 44 20 0 .06 

 24 60 28 44 21 0 .06 

 25 59 28 44 21 0 .06 

 26 59 28 43 22 0 .06 

 27 58 27 43 22 0 .06 

 28 58 27 43 22 0 .06 

 29 58 27 42 23 0 .06 

 30 57 27 42 23 0 .06 

 31 57 26 42 23 0 .06

TOTAL 554 0 1.93 

AVG 63.1 31.1 47.1 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

NOVEMBER

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 56 26 41 24 0 .06 

 2 56 26 41 24 0 .06 
68 

 3 55 25 40 24 0 .06 

 4 55 25 40 25 0 .06 

 5 55 25 40 25 0 .06 

 6 54 24 39 25 0 .07 

 7 54 24 39 26 0 .07 

 8 53 24 39 26 0 .07 

 9 53 24 38 26 0 .07 

 10 53 23 38 27 0 .07 

 11 52 23 38 27 0 .07 

 12 52 23 37 27 0 .06 

 13 51 23 37 28 0 .06 

 14 51 22 37 28 0 .06 

 15 51 22 36 28 0 .06 

 16 50 22 36 29 0 .06 

 17 50 22 36 29 0 .06 

 18 50 21 36 29 0 .06 

 19 49 21 35 30 0 .06 

 20 49 21 35 30 0 .06 

 21 49 21 35 30 0 .06 

 22 48 21 35 30 0 .06 

 23 48 20 34 31 0 .06 

 24 48 20 34 31 0 .06 

 25 48 20 34 31 0 .06 

 26 47 20 33 31 0 .06 

 27 47 19 33 32 0 .06 

 28 47 19 33 32 0 .06 

 29 47 19 33 32 0 .06 

 30 46 19 33 33 0 .06

TOTAL 850 0 1.86 

AVG 50.8 22.1 36.5 

NORMALS 

 FLAGSTAFF, AZ 

 1971 to 2000 

 Latitude: 350

 08' N 

 Longitude: 1110

 40' W 

 Elevation: 7003 Feet 

DECEMBER 

 TEMPERATURE DEGREE DAYS PRECIPITATION 

DATE MAX MIN AVG HDD CDD DAILY

 1 46 18 32 33 0 .06 

 2 46 18 32 33 0 .06 
69 

 3 46 18 32 33 0 .06 

 4 45 18 32 33 0 .06 

 5 45 18 32 34 0 .06 

 6 45 18 31 34 0 .06 

 7 45 17 31 34 0 .06 

 8 45 17 31 34 0 .06 

 9 44 16 31 34 0 .06 

 10 44 16 31 34 0 .06 

 11 44 16 31 35 0 .06 

 12 44 16 30 35 0 .05 

 13 44 16 30 35 0 .05 

 14 44 16 30 35 0 .05 

 15 44 15 30 35 0 .06 

 16 43 16 30 35 0 .06 

 17 43 16 30 35 0 .06 

 18 43 16 30 36 0 .06 

 19 43 16 30 36 0 .06 

 20 43 16 30 36 0 .06 

 21 43 16 30 36 0 .06 

 22 43 16 29 36 0 .06 

 23 43 16 29 36 0 .06 

 24 43 16 29 36 0 .06 

 25 43 16 29 36 0 .06 

 26 43 16 29 36 0 .06 

 27 43 16 29 36 0 .06 

 28 42 16 29 36 0 .06 

 29 42 16 29 36 0 .06 

 30 42 16 29 36 0 .06 

 31 42 16 29 36 0 .06

TOTAL 1085 0 1.83 

AVG 43.7 16.6 30.2 
70 

 FLAGSTAFF, ARIZONA Location: W111 37, N35 13 Rise and Set for the Sun for 2008  Mountain Standard Time 

 Jan Feb Mar Apr May Jun Jul Aug Sep 

Day Rise Set Rise Set Rise Set Rise Set Rise Set Rise Set Rise Set Rise Set Rise S

 h m h m h m h m h m h m h m h m h m h m h m h m h m h m h m h m h m h 

1 735 1725 726 1754 655 1823 612 1848 535 1913 513 1936 516 

194

5 536 1929 559 18

2 735 1726 725 1756 654 1823 611 1849 534 1914 513 1937 516 

194

5 537 1928 600 18

3 735 1727 724 1757 653 1824 610 1850 533 1914 512 1937 517 

194

5 537 1927 601 18

4 735 1727 724 1758 651 1825 608 1851 532 1915 512 1938 517 

194

5 538 1926 602 18

5 736 1728 723 1759 650 1826 607 1852 531 1916 512 1938 518 

194

4 539 1925 602 18

6 736 1729 722 1800 649 1827 606 1852 530 1917 512 1939 518 

194

4 540 1924 603 18

7 736 1730 721 1801 647 1828 604 1853 529 1918 512 1939 519 

194

4 540 1923 604 18

8 736 1731 720 1802 646 1829 603 1854 528 1918 512 1940 519 

194

4 541 1922 605 18

9 736 1732 719 1803 645 1830 602 1855 527 1919 511 1940 520 

194

3 542 1921 605 18

10 736 1733 718 1804 643 1830 600 1856 526 1920 511 1941 521 

194

3 543 1920 606 18

11 735 1734 717 1805 642 1831 559 1856 525 1921 511 1941 521 

194

3 544 1919 607 18

12 735 1734 716 1806 641 1832 558 1857 524 1922 511 1942 522 

194

2 544 1918 607 18

13 735 1735 715 1807 639 1833 556 1858 524 1922 511 1942 522 

194

2 545 1917 608 18

14 735 1736 714 1808 638 1834 555 1859 523 1923 511 1942 523 

194

2 546 1916 609 18

15 735 1737 713 1809 636 1835 554 1900 522 1924 511 1943 524 

194

1 547 1914 610 18

16 734 1738 712 1810 635 1835 552 1900 521 1925 512 1943 524 

194

1 547 1913 610 18

17 734 1739 711 1810 634 1836 551 1901 521 1926 512 1943 525 

194

0 548 1912 611 18

18 734 1740 710 1811 632 1837 550 1902 520 1926 512 1944 526 

193

9 549 1911 612 18

19 733 1741 709 1812 631 1838 549 1903 519 1927 512 1944 526 

193

9 550 1910 613 18
71 

20 733 1742 708 1813 629 1839 547 1904 519 1928 512 1944 527 

193

8 550 1908 613 18

21 733 1743 706 1814 628 1840 546 1905 518 1929 512 1944 528 

193

8 551 1907 614 18

22 732 1744 705 1815 627 1840 545 1905 517 1929 513 1945 528 

193

7 552 1906 615 18

23 732 1745 704 1816 625 1841 544 1906 517 1930 513 1945 529 

193

6 553 1905 616 18

24 731 1746 703 1817 624 1842 543 1907 516 1931 513 1945 530 

193

6 553 1903 616 18

25 731 1747 702 1818 622 1843 541 1908 516 1931 514 1945 531 

193

5 554 1902 617 18

26 730 1748 700 1819 621 1844 540 1909 515 1932 514 1945 531 

193

4 555 1901 618 18

27 729 1749 659 1820 620 1844 539 1909 515 1933 514 1945 532 

193

3 556 1859 619 18

28 729 1750 658 1821 618 1845 538 1910 514 1934 515 1945 533 

193

3 556 1858 619 18

29 728 1751 657 1822 617 1846 537 1911 514 1934 515 1945 534 

193

2 557 1857 620 18

30 727 1752 615 1847 536 1912 514 1935 515 1945 534 

193

1 558 1855 621 18

31 727 1753 614 1848 513 1935 535 

193

0 559 1854 
72 

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). 

 (PB-17800) 

 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) (Revised 

August 2002 3rd Revision) 

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) 
73 

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 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 WSR74C 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) 
74 

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) 

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 18-03-1806, Weather, Water and 

Climate, Vernon Preston, Pocatello Idaho, December 2004. 

270 Climate of San Diego, California, Emmanuel M. Isla, September 2004 

(2nd Edition) 

271 Climate of Las Vegas, Nevada, Andrew S. Gorelow, January 2005, (2nd

Edition) 

272 Climate of Sacramento, California, Revised by: Laura A. Bevan and 

George Cline, June 2005 

273 Climate of Flagstaff, AZ 4th Revision. Mike Staudenmaier, Jr, 

Reginald Preston(R) 

 Paul Sorenson (R) , August 2005 

274 Climate of Prescott, AZ, Bob Fogarty, Mike Staudenmaier Jr., Flagstaff 

WFO, AZ, August 2005. 

275 Climate of San Diego, CA, 3rd Revision. Noel M. Isla, Jennifer Lee, March 

2006 
75 

276 Climate of Reno, NV, Brian Ohara, Reno, NV October 2006 

277 Forecaster's Handbook for Extreme Southwestern California Based On 

Short Term Climatalogical Approximations: Part I - The Marine Layer 

and Its Effect On Precipitation and Heating Ivory J. Small, October 2006 

278 Forecaster's Handbook for Extreme Southwestern California Based On 

Short Term Climatalogical Approximations: Part II – Wind Effects on 

Terrestrial and Marine Environments 

Ivory J. Small, December 2006 

279 Effects of Wildfire in the Mountainous Terrain of Southeast Arizona: An 

Empirical Formula to Estimate 5-Year Peak Discharge from Small PostBurn Watersheds, William B. Reed and Mike Schaffner , June 2007 

NOAA SCIENTIFIC AND TECHNICAL PUBLICATIONS 

The National Oceanic and Atmospheric Administration was established as part of the Department of Commerce 

on October 3, 1970. The mission responsibilities of NOAA are to assess the socioeconomic impact of natural and 

technological changes in the environment and to monitor and predict the state of the solid Earth, the oceans and 

their living resources, the atmosphere, and the space environment of the Earth. 

The major components of NOAA regularly produce various types of scientific and technical information in the 

following kinds of publications. 

PROFESSIONAL PAPERS--Important definitive 

research results, major techniques, and special 

investigations. 

CONTRACT AND GRANT REPORTS--Reports 

prepared by contractors or grantees under NOAA 

sponsorship. 

ATLAS--Presentation of analyzed data generally in 

the form of maps showing distribution of rainfall, 

chemical and physical conditions of oceans and 

atmosphere, distribution of fishes and marine 

mammals, ionospheric conditions, etc.

TECHNICAL SERVICE PUBLICATIONS -- 

Reports containing data, observations, instructions, 

etc. A partial listing includes data serials; 

prediction and outlook periodicals; technical 

manuals, training papers, planning reports, and 

information serials; and miscellaneous technical 

publications. 

TECHNICAL REPORTS--Journal quality with 

extensive details, mathematical developments, or 

data listings. 

TECHNICAL MEMORANDUMS--Reports of 

preliminary, partial, or negative research or 

technology results, interim instructions, and the 

like.

Information on availability of NOAA publications can be obtained from: 
76 

NATIONAL TECHNICAL INFORMATION SERVICE 

U. S. DEPARTMENT OF COMMERCE 

5285 PORT ROYAL ROAD 

SPRINGFIELD, VA 22161