Climate data by elevation in the Great Smoky Mountains: 

a database and graphical displays for 1947 – 1950 with 

comparison to long-term data

U.S. Department of the Interior

U.S. Geological Survey

Data Series Report DS 115
Climate data by elevation in the Great Smoky 

Mountains: a database and graphical displays for 

1947 – 1950 with comparison to long-term data 

 

 Richard T. Busing, Luther A. Stephens and Edward E.C. Clebsch 

Data Series Report DS 115 

U.S. Department of the Interior 

U.S. Geological Survey 

i
U.S. Department of the Interior 

Gale A. Norton, Secretary 

U.S. Geological Survey 

Charles G. Groat, Director 

U.S. Geological Survey, Reston, Virginia 2005 

For product and ordering information:

World Wide Web: http://www.usgs.gov/pubprod

Telephone: 1-888-ASK-USGS

For more information on the USGS—the Federal source for science about the Earth, 

its natural and living resources, natural hazards, and the environment:

World Wide Web: http://www.usgs.gov 

Telephone: 1-888-ASK-USGS 

ii
Contents 

Abstract................................................................................................................................................................................1

Introduction .........................................................................................................................................................................1

Methods ...............................................................................................................................................................................2

The 1947-1950 data .........................................................................................................................................................2

Comparison of the sample to the long-term record .................................................................................................2

Sources of the long-term data summaries ................................................................................................................2

Results and discussion......................................................................................................................................................3

The short-term sample vs. the long-term record......................................................................................................3

Climatic patterns 1947 - 1950 ........................................................................................................................................3

Temperature ................................................................................................................................................................3

Precipitation.................................................................................................................................................................3

Relative humidity.........................................................................................................................................................3

Vapor pressure deficit................................................................................................................................................4

Cloud cover..................................................................................................................................................................4

Potential evapotranspiration ....................................................................................................................................4

Soil moisture ................................................................................................................................................................4

Potential applications and limitations.........................................................................................................................4

Use of the database .......................................................................................................................................................5

Summary of major climatic patterns ...........................................................................................................................5

Acknowledgements ...........................................................................................................................................................6

References...........................................................................................................................................................................7

iii
List of Figures 

Figure 1. Map showing the four climate stations in Great Smoky Mountains National Park from 

which the database was developed. The sites, marked with black circles, are located along paved 

roads from park headquarters (near Gatlinburg) to Clingmans Dome. ....................................................... 8

Figure 2. Comparison of the study period climate (1947-1950) to long-term climate (ca. 1930-2003) at 

the Gatlinburg SW station (1460 ft). Variables include A) annual temperature, and B) annual 

precipitation. Standard deviations are for the long-term data. ................................................................... 9

Figure 3. Comparison of monthly mean temperatures during the study period (1947-1950) to longterm values (ca. 1930-2003) at the Gatlinburg SW station (1460 ft). ........................................................... 10

Figure 4. Comparison of monthly precipitation during the study period (1947-1950) to long-term 

values (ca. 1930-2003) at the Gatlinburg SW station (1460 ft). .................................................................... 10

Figure 5. Monthly temperature means (1947-1950) by elevation. .............................................................. 11

Figure 6. Mean maximum temperature (1947-1950) by month and elevation.......................................... 11

Figure 7. Mean minimum temperature (1947-1950) by month and elevation........................................... 12

Figure 8. Maximum temperature (1947-1950) by month and elevation. .................................................... 12

Figure 9. Minimum temperature (1947-1950) by month and elevation. ..................................................... 13

Figure 10. Temperature lapse rates (1947-1950) by month for A) 1460 to 3850 ft elevation, B) 1460 to 

5000 ft elevation, and C) 1460 to 6300 ft elevation.......................................................................................... 15

Figure 11. Monthly precipitation (1947-1950) by elevation.......................................................................... 16

Figure 12. Daily precipitation (1947-1950) by month and elevation. .......................................................... 16

Figure 13. Precipitation days (1947-1950) by month and elevation............................................................ 17

Figure 14. Consecutive precipitation days (1947-1950) by month and elevation. ................................... 17

Figure 15. Consecutive dry days (1947-1950) by month and elevation...................................................... 18

Figure 16. Monthly relative humidity (1947-1950) by elevation................................................................... 18

Figure 17. Monthly vapor pressure deficit (1947-1950) by elevation......................................................... 19

Figure 18. Monthly cloud cover (1947-1950) at A) 1460 ft elevation, B) 3850 ft elevation, C) 5000 ft 

elevation, and D) 6300 ft elevation.................................................................................................................... 21

Figure 19. Monthly mean soil moisture (1947-1950) at A) 1460 ft elevation, B) 3850 ft elevation, C) 

5000 ft elevation, and D) 6300 ft elevation. ...................................................................................................... 23

Figure 20. Monthly mean soil moisture balance (1947-1950) at A) 1460 ft elevation, B) 3850 ft 

elevation, C) 5000 ft elevation, and D) 6300 ft elevation................................................................................ 25

Figure 21. Daily mean soil moisture balance (1947-1950) at A) 1460 ft elevation, B) 3850 ft elevation, 

C) 5000 ft elevation, and D) 6300 ft elevation. ................................................................................................. 27

Figure 22. Monthly soil moisture minima and maxima (1947-1950) by elevation. ................................... 28

iv
Climate data by elevation in the Great Smoky 

Mountains: a database and graphical displays for 

1947 – 1950 with comparison to long-term data 

Richard T. Busing, Luther A. Stephens and Edward E.C. Clebsch 

Abstract 

A climate data set is presented for four sites spanning the elevation gradient in the Great 

Smoky Mountains from Gatlinburg to Clingmans Dome. Monthly mean values for cloud cover, 

temperature, humidity, precipitation, and soil moisture are included. Stephens (1969) is the source 

of all summarized mean monthly data. Values are the averages of four years (1947-1950) with 

moderate to high precipitation. Graphical displays show strong climatic patterns of variation 

among seasons and elevations. The upper stations had lower temperatures and higher precipitation 

totals; however, temperature lapse rates and variation in vapor pressure deficits decreased at upper 

elevations. To examine how well the four-year sample represents the long-term climate, 

temperature and precipitation for the Gatlinburg (1460 ft elevation at park headquarters) station 

were compared between the years in the sample and the years in the full record from 1928 to 2003. 

Trends related to season and elevation are consistent with earlier studies and provide a basis for 

interpretation of climate dynamics in the southern Appalachian Mountains. 

Introduction 

The broad range of elevations in the Great Smoky Mountains (<1000 to 6642 ft asl) 

contributes to the wide variety of climates therein (Shanks 1954). At the lower elevations (ca. 1000 

ft) the climate is humid mesothermal (Thornthwaite 1948, Shanks 1954) with precipitation 

distributed throughout the year. At the uppermost elevations, which are among the highest attained 

in the Appalachian chain, the relatively cool, wet climate is perhumid microthermal. It supports 

evergreen coniferous forest vegetation rather than the deciduous forest vegetation typical of lower 

elevations. Total annual precipitation in the high-elevation coniferous forests rivals that of some of 

the wettest regions of the United States. This climatic gradient occurs within an air line distance of 

less than 11 miles. Four climate stations along the gradient in Great Smoky Mountains National 

Park serve as the basis for the database presented here. The purpose of this report is to make these 

data readily available and to facilitate their interpretation. 

1
Methods 

The 1947-1950 data 

A set of monthly mean climate data from four climate stations in Great Smoky Mountains 

National Park was entered into computer spreadsheet files. Monthly mean summaries for four 

years (1947-1950) were taken from tables of numeric data in Stephens (1969). The four climate 

stations were located in Sevier County, Tennessee or in Swain County, North Carolina (Fig1; 

latitude 36o

N, longitude 83oW). They spanned the elevation gradient from 1460 to 6300 ft (Table 

1). The station at 1460 ft was located at park headquarters near Gatlinburg; the station at 3850 ft 

was located at the Alum Cave Bluffs parking lot; the station at 5000 ft was located near Newfound 

Gap; and the station at 6300 ft was located at the Forney Ridge parking area just south of the 

Clingmans Dome summit. Climate station sites were discussed in detail by Shanks (1954). 

Data collection involved instrumentation (Shanks 1954) and field observation. Precipitation 

type and sky conditions were noted once a day from visual observations at each station. Other raw 

data consisted of hourly temperature and relative humidity, and daily precipitation amount. 

Missing data were filled in with interpolated estimates (Stephens 1969). 

The hourly data were compiled into daily values including maximum, minimum, range and 

24-hr mean. Monthly values were then computed as the sum of daily means divided by the number 

of days. Monthly mean values for the four-year period of study were used for this dataset. Soil 

moisture balance calculations presented here were based on daily as well as monthly mean 

estimates of potential evapotranspiration (Thornthwaite 1957). The monthly calculations were 

based on monthly mean temperature, monthly total precipitation, and latitude. The daily 

calculations were based on daily mean temperature and daily mean precipitation. Further details on 

data compilation methods are provided by Stephens (1969). 

Comparison of the sample to the long-term record 

To examine how well the four-year sample represents the long-term climate, temperature 

and precipitation for the Gatlinburg (1460 ft elevation at park headquarters) station were compared 

between the years in the sample and the years in the full record from 1928 to 2003. Annual values 

were compared first, then monthly values were compared. Similar comparisons at higher elevation 

stations were not made because of the relatively incomplete long-term records at those stations. 

Sources of the long-term data summaries 

While all short-term data (1947-1950), which constitute the majority of the data presented 

in this report, were taken from Stephens (1969), long-term data (ca. 1928 to 2003) were taken from 

the Southeast Regional Climate Center internet site (http://www.dnr.state.sc.us/climate/sercc/). The 

data records of monthly mean temperature and monthly total precipitation for the Gatlinburg SW 

station (at park headquarters) were obtained in 2004. They spanned the period from the late 1920s 

to 2003. 

2
Results and discussion 

The short-term sample vs. the long-term record 

Comparison of the sample of four years selected by Stephens (1969) to the long-term record 

(1928 to 2003; >60 yr with fairly complete temperature and precipitation data) indicates that, on 

average, the years sampled are wetter and cooler than the long-term record. Mean annual values 

from the years sampled lie within one standard deviation of the long-term means, however (Figure 

2a & b). 

Mean monthly values showed more variation, with values from the four-year sample often 

deviating substantially from the long-term values. For example, means of monthly temperatures 

were more than one standard deviation less than the long-term means in August, September and 

November (Figure 3). The mean of monthly precipitation was about one standard deviation greater 

than the long-term mean in January (Figure 4). On average, the short-term study had cooler late 

summer and fall temperatures, and wetter winters than the long-term record. 

Climatic patterns 1947 - 1950 

Temperature 

Temperature decreased with elevation and varied strongly with season (Figure 5). Mean 

maximum monthly temperatures occurred in July (Figure 6). Mean minimum monthly 

temperatures occurred in December (Figure 7). Maximum temperatures were attained in July and 

August, depending on the station (Figure 8). Minimum temperatures occurred in November and 

January (Figure 9). The lapse rate, or decrease in temperature with increasing elevation, declined 

with increasing elevation (Figure 10a, b & c). It also declined in winter. 

Precipitation 

Monthly precipitation tended to increase substantially with elevation (Figure 11). The 

relatively high levels of winter precipitation at the 5000 ft site were an exception to this trend. 

Nonetheless, annual precipitation was highest at the 6300 ft site. Monthly precipitation peaked in 

January and August. September and October had relatively low precipitation. Daily precipitation 

followed the same pattern, but there were some differences; for instance, the months having 

maximum and minimum values often differed (Figure 12). 

The temporal distribution of rainfall showed seasonal patterns. The number of precipitation 

days peaked in winter and summer (Figure 13). The same was true for the number of consecutive 

precipitation days (Figure 14). At all stations the number of consecutive dry days peaked in the fall 

(Figure 15). 

Relative humidity 

Relative humidity was high (>70 %) at all stations. It tended to peak in January and August 

(Figure 16). It was low in April and November. A simple elevation gradient for relative humidity 

was not evident. The mid-elevation stations tended to have maximal relative humidity. 

Presumably, topography had a strong influence on relative humidity, with concave, north-facing 

sites (e.g. the station at 3850 ft; Table 1) having higher humidity. 

3
Vapor pressure deficit 

The vapor pressure deficit indicates the atmospheric capacity for additional water regardless 

of the temperature. Deficit values were high at the low-elevation site, particularly during spring 

and summer (Figure 17). Differences among the other three sites were relatively minor. Annual 

variation was evident; the greatest deficits occurred in April and May. 

Cloud cover 

Cloudiness varied by season and elevation (Figure 18 a, b, c & d). Spring and fall months 

had the least cloudiness. Fog was most frequent in winter. The frequency of clear and scattered 

cloudy days decreased with elevation. The frequency of fog increased with elevation. 

Potential evapotranspiration 

Potential evapotranspiration peaked in summer when temperatures were high (Figure 19 a, 

b, c & d). Rarely did potential evaporation exceed precipitation; this occurred only at the lowelevation station. The estimates of potential evapotranspiration based on monthly values (Figure 20 

a, b, c & d) were often less than those based on daily values (Figure 21 a, b, c & d). This resulted 

primarily from cold months with occasional daily values elevated above the monthly mean. 

Soil moisture 

Soil moisture deficits were not projected when the monthly values were used for estimation 

(Figure 20 a, b, c & d). By contrast, moisture deficits were projected for May through October 

when daily values were used (Figure 21 a, b, c & d). The soil moisture balance increased with 

elevation. It peaked in spring and winter. Overall, minimum values were projected for the low 

elevation site in summer and fall (Figure 22). 

Potential applications and limitations 

The database has many potential uses in addition to the fundamental analyses demonstrated 

above. The short-term climate data can be further analyzed for relationships among variables. It 

may also provide baseline information for long-term studies of climate. Ecological implications of 

climate can be explored as well. For example, patterns of soil moisture have strong implications 

for vegetation. However, the soil moisture balance estimates presented here may be inadequate for 

ecological analyses (Stephens 1969). More advanced techniques may be helpful in estimating 

climate effects on soil moisture. In such cases the precipitation and temperature data should be 

very useful. Many existing models can make use of these monthly temperature and precipitation 

statistics to simulate climate and the ecological environment. For example, these data can be used 

in parameterization of climate-driven models of hydrology, nutrient transport, and vegetation. 

It is possible to apply these data to other sites within the Great Smoky Mountains. For 

example, the daymet climate dataset (http://www.daymet.org) consists of daily climate values for 

landscapes, including the Great Smoky Mountains, extrapolated from nearby climate stations 

(1980-1997 data). The climate stations in this report span almost the entire elevation range of the 

southern Appalachian Mountains. Yet, not all microsite conditions are represented. For this 

reason, caution must be used in extrapolating these data to other sites in the region. Identification 

and consideration of important microsite influences are necessary. 

4
Use of the database 

The data are stored in a single file (CLIMGSM1.wk1). Different types of data are presented 

in tabular format with separate tables for each type of climate information. The tables are 

presented in a series, from left to right, in the file. Each line in the database usually represents a 

monthly value for the given climate variable. Identification of variables or climate station sites 

typically occurs in the first row. Further information is provided to the left of each table. Most 

values are present, but a few values are missing. Measures are in English units unless noted 

otherwise. The major variables and abbreviations are described in Table 2. 

Summary of major climatic patterns 

Temperature decreased with elevation, yet the lapse rate diminished at higher elevations. 

Inversions and cold-air drainage are likely explanations for the diminished lapse rate at high 

elevations. The lapse rate also decreased from a maximum in July to a minimum in December and

January. Precipitation increased with elevation. Amounts at the two highest stations were 

influenced by microclimate and precipitation type. The 6300 ft station had the highest precipitation 

in summer, but the 5000 ft station had the highest precipitation in winter. Relative humidity 

increased from low to middle elevations, but was also affected by microclimate. The range of 

relative humidity decreased in summer. Declines in vapor pressure deficits with elevation were 

relatively minor above the middle elevations. 

Soil moisture balance calculations, based on several simplifying assumptions, suggested 

that soil moisture content increased with elevation. By contrast, estimates of evapotranspiration 

decreased with elevation. Although water balance could not be calculated accurately from climate 

data alone, these climate data were sufficient for exploratory analyses. Soil moisture minima 

occurred at low elevations in late summer and early fall. Indications of extremely low soil moisture 

were not obtained at any elevation or season. 

5
Table 1. Climate stations in the database. 

Station name Site Description 

Gatlinburg., Sevier Co., Tennessee 1460 ft elev. in a valley bottom 

Alum Cave Bluffs Parking Area, Sevier Co., Tennessee 3850 ft elev. in an upper valley facing N 

Newfound Gap, Sevier Co., Tennessee 5000 ft elev. near a ridge crest facing N 

Clingmans Dome, Swain Co., North Carolina 6300 ft elev. on an upper slope facing S 

Table 2. Variables in the database.

Variable name Description Units or format

Month Month of the year Single character 

Clear No clouds Percent frequency 

SCloudy Scattered clouds Percent frequency 

PCloudy Partly cloudy Percent frequency

Cloudy Clouds Percent frequency

Overcast Overcast sky Percent frequency 

Fog Low fog Percent frequency 

MeanTLR Mean temperature lapse rate Deg. F per 1000 ft

MaxTLR Maximum temperature lapse rate Deg. F per 1000 ft

MinTLR Minimum temperature lapse rate Deg. F per 1000 ft

MeanT Mean temperature Deg. F 

MeanMaxT Mean maximum temperature Deg. F 

MeanMinT Mean minimum temperature Deg. F 

Temp Mean temperature Deg. F 

PET Potential evapotranspiration Inches

Prec Mean precipitation Inches

P-PET Prec minus PET Inches

SM Soil moisture content Inches 

MD Soil moisture deficit Inches 

MS Soil moisture surplus Inches 

SMB Soil moisture balance Inches 

Acknowledgements 

Mary Lou Taisey’s assistance in preparing the database file is greatly appreciated. The 

climate data were originally made available by the Hydraulic Data Branch of the Tennessee Valley

Authority. Dr. Jason Fridley and Dr. Ken Orvis kindly provided objective reviews of the draft 

manuscript. 

6
References 

Shanks, R.E. 1954. Climates of the Great Smoky Mountains. Ecology 35:353-361. 

Stephens, L.A. 1969. A comparison of climatic elements at four elevations in the Great Smoky 

Mountains National Park. M.S. Thesis, University of Tennessee, Knoxville, Tennessee. 

Thornthwaite, C.W. 1948. An approach toward a rational classification of climate. Geogr. Rev. 

38:55-94. 

Thornthwaite, C.W. 1957. Instructions and tables for computing potential evapotranspiration and 

the water balance. Drexel Inst. Tech., Lab. Of Climatology, Publ. in Climatology, No. 1, 

Centerton. 

7
Figure 1. Map showing the four climate stations in Great Smoky Mountains National Park from 

which the database was developed. The sites, marked with black circles, are located along paved 

roads from park headquarters (near Gatlinburg) to Clingmans Dome. 

8
A) LONG-TERM TEMPERATURE VS. STUDY

50

52

54

56

58

TEMPERATURE

ANNUAL MEAN (Deg. F)

Long-term mean

Study mean

B) LONG-TERM PRECIPITATION VS. STUDY

40

45

50

55

60

65

70

PRECIPITATION

ANNUAL P

RECIPITATIO

N (in)

Long-term mean

Study mean

Figure 2. Comparison of the study period climate (1947-1950) to long-term climate (ca. 1930-2003) at 

the Gatlinburg SW station (1460 ft). Variables include A) annual temperature, and B) annual 

precipitation. Standard deviations are for the long-term data. 

9
LONG-TERM TEMPERATURE VS. STUDY (1460 ft)

30

35

40

45

50

55

60

65

70

75

80

J F M A M J J A S O N D

MONTH

MONTHLY MEAN TEMPERATURE (Deg. F)

Long-term mean

plus Std. Dev.

minus Std. Dev.

Study mean

Figure 3. Comparison of monthly mean temperatures during the study period (1947-1950) to longterm values (ca. 1930-2003) at the Gatlinburg SW station (1460 ft). 

LONG-TERM PRECIPITATION VS. STUDY (1460 ft)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

J F M A M J J A S O N D

MONTH

MONTHLY PRECIPITATION (in)

Long-term mean

plus Std. Dev.

minus Std. Dev.

Study mean

Figure 4. Comparison of monthly precipitation during the study period (1947-1950) to long-term 

values (ca. 1930-2003) at the Gatlinburg SW station (1460 ft). 

10
MEAN TEMPERATURE 

0

10

20

30

40

50

60

70

80

 J F M A M J J A S O N D

MONTH

TE

MPERA

TURE (

Deg. F)

 1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 5. Monthly temperature means (1947-1950) by elevation. 

MEAN MAXIMUM TEMPERATURE

0

10

20

30

40

50

60

70

80

90

 J F M A M J J A S O N D

MONTH

TEMPERATU

RE (Deg. F)

 1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 6. Mean maximum temperature (1947-1950) by month and elevation. 

11
MEAN MINIMUM TEMPERATURE

0

10

20

30

40

50

60

70

 J F M A M J J A S O N D

MONTH

TEMPERATU

RE (Deg. F)

 1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 7. Mean minimum temperature (1947-1950) by month and elevation. 

MAXIMUM TEMPERATURE 

40

50

60

70

80

90

100

110

 J F M A M J J A S O N D

MONTH

T

E

MPERATURE (

D

e

g. F)

 Max 1460 ft

 Max 3850 ft

 Max 5000 ft

 Max 6300 ft

Figure 8. Maximum temperature (1947-1950) by month and elevation. 

12
MINIMUM TEMPERATURE

-30

-20

-10

0

10

20

30

40

50

60

J F M A M J J A S O N D

MONTH

TEMPERATURE (Deg. F)

 Min 1460 ft

 Min 3850 ft

 Min 5000 ft

 Min 6300 ft

Figure 9. Minimum temperature (1947-1950) by month and elevation. 

13
A) TEMPERATURE LAPSE RATE (1460-3850 ft)

0

1

2

3

4

5

6

7

 J F M A M J J A S O N D

MONTH

DEG. (F)/ELEVATI

ON (1000 ft)

MeanTLR

MaxTLR

MinTLR

B) TEMPERATURE LAPSE RATE (1460-5000 ft)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

 J F M A M J J A S O N D

MONTH

DEG. (F)/ELEVATION (1000 ft)

MeanTLR

MaxTLR

MinTLR

14
C) TEMPERATURE LAPSE RATE (1460-6300 ft)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

 J F M A M J J A S O N D

MONTH

DEG. (F)/ELEVATION (1000 ft)

MeanTLR

MaxTLR

MinTLR

 

Figure 10. Temperature lapse rates (1947-1950) by month for A) 1460 to 3850 ft elevation, B) 1460 to 

5000 ft elevation, and C) 1460 to 6300 ft elevation. 

15
MONTHLY PRECIPITATION

0

2

4

6

8

10

12

14

J F M A M J J A S O N D

MONTH

PRECIPITATION (in)

1460 ft

3850 ft

5000 ft

6300 ft

Figure 11. Monthly precipitation (1947-1950) by elevation. 

DAILY PRECIPITATION

0.20

0.30

0.40

0.50

0.60

0.70

0.80

J F M A M J J A S O N D

MONTH

PRECIPITATION (in)

 1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 12. Daily precipitation (1947-1950) by month and elevation. 

16
PRECIPITATION DAYS

8.00

10.00

12.00

14.00

16.00

18.00

J F M A M J J A S O N D

MONTH

DAYS PER M

ONTH

 1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 13. Precipitation days (1947-1950) by month and elevation. 

CONSECUTIVE PRECIPITATION DAYS

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

J F M A M J J A S O N D

MONTH

DAYS

 1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 14. Consecutive precipitation days (1947-1950) by month and elevation. 

17
CONSECUTIVE DRY DAYS

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

J F M A M J J A S O N D

MONTH

DAYS

1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 15. Consecutive dry days (1947-1950) by month and elevation. 

MONTHLY RELATIVE HUMIDITY

60

65

70

75

80

85

90

95

100

 J F M A M J J A S O N

MONTH

RELATIVE HUMIDITY (%)

1460 ft

 3850 ft

 5000 ft

 6300 ft

Figure 16. Monthly relative humidity (1947-1950) by elevation. 

18
MONTHLY VAPOR PRESSURE DEFICIT

0

0.5

1

1.5

2

2.5

3

3.5

 J F M A M J J A S O N D

MONTH

PRESSURE DEFICIT (mm Hg)

1460 ft

3850 ft

5000 ft

6300 ft

Figure 17. Monthly vapor pressure deficit (1947-1950) by elevation. 

19
A) CLOUD COVER (1460 ft)

0

5

10

15

20

25

30

35

40

45

 J F M A M J J A S O N D

MONTH

FREQUENCY (%)

Clear

SCloudy

PCloudy

Cloudy

Overcast

Fog

B) CLOUD COVER (3850 ft)

0

5

10

15

20

25

30

35

40

45

50

 J F M A M J J A S O N D

MONTH

FREQUENCY (%)

Clear

SCloudy

PCloudy

Cloudy

Overcast

Fog

20
C) CLOUD COVER (5000 ft)

0

5

10

15

20

25

30

35

40

45

 J F M A M J J A S O N D

MONTH

FREQUENCY (%)

Clear

SCloudy

PCloudy

Cloudy

Overcast

Fog

D) CLOUD COVER (6300 ft)

0

5

10

15

20

25

30

35

40

45

 J F M A M J J A S O N D

MONTH

FREQUENCY (%)

Clear

SCloudy

PCloudy

Cloudy

Overcast

Fog

Figure 18. Monthly cloud cover (1947-1950) at A) 1460 ft elevation, B) 3850 ft elevation, C) 5000 ft 

elevation, and D) 6300 ft elevation. 

21
A) ANNUAL SOIL MOISTURE BALANCE (1460 ft, monthly mean)

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

J F M A M J J A S O N

MONTH

MONTHLY VALUE (in or deg. F)

 Temp.

 PET

 Prec.

 P-PET

 SM

MD

 MS

 SMB

B) ANNUAL SOIL MOISTURE BALANCE (3850 ft, monthly means)

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

J F M A M J J A S O N D

MONTH

MONTHLY VALUE (in or deg. F)

Temp.

 PET

Prec.

 P-PET

 SM

 MD

 MS

 SMB

22
C) SOIL MOISTURE BALANCE (5000 ft, monthly means)

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

J F M A M J J A S O N D

MONTH

MONTHLY VALUE (in or deg. F)

Temp.

PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

D) SOIL MOISTURE BALANCE (6300 ft, monthly means)

0

10

20

30

40

50

60

J F M A M J J A S O N D

MONTH

MONTHLY VALUE (in or deg. F)

 Temp.

 PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

 

Figure 19. Monthly mean soil moisture (1947-1950) at A) 1460 ft elevation, B) 3850 ft elevation, C) 

5000 ft elevation, and D) 6300 ft elevation. 

23
A) ANNUAL SOIL MOISTURE BALANCE (1460 ft, monthly means)

0

2

4

6

8

10

12

14

16

18

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

 PET

 Prec.

 P-PET

 SM

MD

 MS

 SMB

B) ANNUAL SOIL MOISTURE BALANCE (3850 ft, monthly means)

0

2

4

6

8

10

12

14

16

18

20

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

 PET

Prec.

 P-PET

 SM

 MD

 MS

 SMB

24
C) SOIL MOISTURE BALANCE (5000 ft, monthly means)

0

5

10

15

20

25

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

D) SOIL MOISTURE BALANCE (6300 ft, monthly means)

0.00

4.00

8.00

12.00

16.00

20.00

24.00

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

 PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

 

Figure 20. Monthly mean soil moisture balance (1947-1950) at A) 1460 ft elevation, B) 3850 ft 

elevation, C) 5000 ft elevation, and D) 6300 ft elevation. 

25
A) SOIL MOISTURE BALANCE (1460 ft, daily means)

-2

0

2

4

6

8

10

12

14

16

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

 PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

B) SOIL MOISTURE BALANCE (3850 ft, daily means)

0

2

4

6

8

10

12

14

16

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

 PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

26
C) SOIL MOISTURE BALANCE (5000 ft, daily means)

0

2

4

6

8

10

12

14

16

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

 PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

D) SOIL MOISTURE BALANCE (6300 ft, daily means)

0

2

4

6

8

10

12

14

16

J F M A M J J A S O N D

MONTH

MONTHLY ESTIMATE (in)

 PET

 Prec.

 P-PET

 SM

 MD

 MS

 SMB

Figure 21. Daily mean soil moisture balance (1947-1950) at A) 1460 ft elevation, B) 3850 ft elevation, 

C) 5000 ft elevation, and D) 6300 ft elevation. 

27
SOIL MOISTURE MINIMA & MAXIMA

7.00

8.00

9.00

10.00

11.00

12.00

13.00

J F M A M J J A S O N D

MONTH

MOISTURE (in)

 Max 1460 ft

 Min

 Max 3850 ft

 Min

 Max 5000 ft

 Min

 Max 6300 ft

 Min

Figure 22. Monthly soil moisture minima and maxima (1947-1950) by elevation. 

28