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Comparative Climate
 
Wyoming
click here to view a precipitation map of wyoming
  Pan Evaporation
 

Standard daily pan evaporation is measured using the four-foot diameter Class A evaporation pan. The pan water level reading is adjusted when precipitation is measure to obtain the actual evaporation. Most Class A pans are installed aboveground, allowing effects such as radiation on the side walls and heat exchnges with the pan material. These effects tend to increase the evaporation totals. The amounts can then be adjusted by multiplying the totals b 0.70 or 0.80 to more closely estimate the evaporation from naturally existing urfaces such as a shallow lake, wet soil or other moist natural surfaces.

Many stations do not measure pan evaportation during winter months. A "0.00" total indicates no measuement is taken.

Stations marked with an asterisk * have estimated totals computed from meteorological measurements using a form of the Penman equation.

 
 
 
period of record
jan
feb
mar
apr
may
jun
july
aug
sept
oct
nov
dec
year
Anchor Dam
1961-1979
M
M
M
M
6.46
7.57
9.66
8.31
5.95
5.33
M
M
43.28
Boysen Dam
1948-2002
M
M
M
5.44
6.72
8.24
9.86
9.08
5.92
3.20
M
M
48.46
Casper Airport *
 
1.90
1.90
3.00
4.70
6.90
8.80
10.60
9.90
6.70
5.20
2.40
1.80
63.70
Cheyenne Airport *
 
2.40
2.40
3.30
5.30
7.00
8.20
9.20
8.60
6.20
4.80
3.00
2.50
62.80
Gillette 2 E
1925-2002
M
M
M
4.52
6.40
7.50
9.88
9.44
6.18
4.36
2.39
M
50.67
Green River
1915-2002
M
M
M
M
8.22
9.71
11.08
9.80
6.82
4.62
M
M
50.25
Heart Mountain
1949-2002
M
M
M
3.50
5.83
6.37
7.35
6.68
4.38
3.43
M
M
37.54
Lander Airport *
 
1.10
1.50
2.80
4.30
6.40
8.00
9.90
9.10
5.60
3.60
1.50
1.10
54.80
Laramie 2 NW
1966-2002
M
M
M
M
8.21
10.26
10.71
9.58
7.48
4.76
M
M
51.00
Morton 1 NW
1949-1968
M
M
M
3.91
5.59
6.73
8.27
7.31
4.96
3.35
M
M
40.12
Pathfinder Dam
1948-1991
M
M
3.20
5.07
6.78
8.78
10.53
9.75
7.17
4.95
2.81
M
59.04
Seminoe Dam
1948-2002
M
M
M
M
5.24
8.27
8.99
8.12
5.59
M
M
M
36.21
Sheridan Airport *
 
1.00
1.10
2.30
4.00
5.60
6.60
8.60
7.90
4.60
3.30
1.50
1.20
48.00
Sheridan Field Stn
1920-2002
M
M
M
3.55
6.32
7.87
10.26
9.71
6.46
M
M
M
44.17
Whalen Dam
1949-1991
M
M
3.32
5.17
7.44
9.00
10.39
9.09
6.24
4.18
M
M
54.83
 
  State Extremes
 
* Also at earlier dates at the same time or other places
 
 
date or year
location
value
Record Highest Temp
12 Jul 1900
Basin
114.00
Record Lowest Temp
9-Feb-33
Riverside R.S.
-66.00
Highest Average Annual Temp
  
Lingle 2 S
49.90
Lowest Average Annual Temp
  
Darwin Ranch
30.80
Consecutive Days Max >= 70
Jul-Aug 1964
Basin
41 days
Consecutive Days Min <= 32
Oct 67-Jul 68
Kendall
277 days
       
Record Maximum Annual Precip
1945
Grassy Lake Dam
55.46
Record Minimum Annual Precip
1960
Lysite
1.28
Record Maximum 24-hour Precip
1-Aug-85
Cheyenne
6.06
Highest Average Annual Precip
  
Snake River
32.31
Lowest Average Annual Precip
  
Lysite
5.11
Consecutive Days Measurable Precip
Jan-Feb 1950
Moose
25 days
Consecutive Days with no Measurable Precip
Nov 87-Apr 88
Deaver
180 days
       
Record Maximum Winter Snowfall
1921-22
Bechler River
491.60
Record Maximum 1-Day Snowfall
14-Mar-73
Burgess Junction
38.00
Highest Average Annual Snowfall
  
Snake River
270.10
 
  Precipitation
(mean monthly & annual number of hrs with measurable precip with % of hrs and maximum 1-hr totals)
 

* = Less than 1/2 hour

Maximum 1-hour totals are based on data from top of the hour. Maximum 60-minute totals will be greater.
 
 
period of record
jan
feb
mar
apr
may
jun
july
aug
sept
oct
nov
dec
year
hour
inches
Casper
1976-1999
32
33
40
45
52
30
18
15
23
33
37
32
390
4
1.74
Cheyenne
1976-1999
23
24
38
47
55
33
28
28
25
26
29
24
380
4
3.51
Lander
1976-1999
25
24
40
50
53
24
15
12
23
28
35
24
353
4
0.83
Sheridan
1948-1999
39
36
49
59
55
40
18
16
33
33
36
34
452
5
1.21
 
  Sunshine Days
(mean monthly & annual % of possible sunshine)
 

Only the first order stations record possible sunshine.

For more information click here on Western States, Alaska or Hawaii and Pacific Island
 
 
jan
feb
mar
apr
may
jun
july
aug
sept
oct
nov
dec
annual
Cheyenne
64
67
67
63
61
67
69
68
70
69
61
60
66
Lander
65
68
70
66
64
72
75
75
72
67
58
61
68
Sheridan
57
60
63
60
60
65
75
75
68
62
53
55
63