National Weather Service United States Department of Commerce

Dense Fog for the Center of the Nation; Severe Thunderstorms Across the South; Parade of Pacific Storms Continue

Series of Pacific storms will continue to significantly impact portions of the West through this last weekend of 2024; Strong winds, high surf, heavy lower elevation rain and heavy mountain snow expected. Across the Plains, low visibility and dense fog will make for travel difficulties as warmer air lifts north. This will fuel severe thunderstorms across several southern states on Saturday. Read More >

Riverton Climate Summary Banner

 

 

...Highlights of 2015...

  • Annual - ...7th Warmest Year on Record (1918-2015), 122 percent of normal precipitation, 130 percent of normal annual snowfall and the 15th snowiest year on record.
  • Latest First Freeze:  October 12, 2015
  • Monthly Temperatures: Warmest September, 2nd Warmest October, 5th Warmest June (over last 97 years, period of record 1918-2015).
  • Montly Precipitation: 2nd Wettest February, 9th Wettest May, 7th Wettest November
  • Montly Snowfall: 2nd Snowiest February and November.

Temperature Banner

 

 

  

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2015
 Average High  29.4 39.3 50.8 59.8 62.6 83.8 84.4 85.7 81.7 66.0 42.9 28.8 59.6
 Mean High (1981-2010 Normals) 31.0 37.4 49.6 60.3 69.2 79.4 88.2 86.7 74.9 60.0 43.1 29.5 59.1
 Average Low  9.8  17.2 23.8 32.5 41.1 53.0 53.2 52.2 45.6  37.4  16.1 5.1 32.3
 Mean Low (1981-2010 Normals) 6.2 11.0 22.5 30.6 40.1 48.1 54.0 51.4 41.4 30.0 17.6 5.4 29.9
 Average Temperature  19.6 28.3 37.3 46.2 51.9 68.4 68.8 69.0 63.7 51.7  29.5 17.0 46.0
 Mean Average Temperature (1981-2010 Normals) 18.6 24.2 36.1 45.4 54.6 63.8 71.1 69.0 58.2 45.0 30.3 17.4 44.5
 Departure from Normal  1.0 4.1 1.2 0.8 -2.7 4.6  -2.3 0.0 5.5 6.7 -0.8 - 0.4 1.5
 Rank - Coldest to Warmest
 97 years of record
(P.O.R 1918-2015)
66 79 78 68  26  90  20 62 97 96 51 41 85
 Highest Daily Maximum  51 60 75 79 79 95 96 97 91 84 67  55 97
 Date of Occurrence  18 13 28 29 30  27 4  14  1,2,13  10  1,3  9 8/14
 Lowest Daily Minimum -21 -17 -17 18 28  45 42  36  36  24   -8  -14  -21
 Date of Occurrence 1 23 4 3 11  2  29  23  18  28,29  21  28 1/1
 Number of Days with:                          
    Maximum >= 90° 0 0 0 0 0 7 8 13  3  0  0 0 31
    Maximum <= 32° 16 11 6 0  0  0 0  0  0  0  7  17 57
    Minimum <= 32° 31 28 22 14  1  0  0  0  0  9  28  31 164
    Minimum <= 0°  5 2 2 0  0  0  0  0  0  0  5  9 23
 Record Highs Set or Tied 0 1 0 0  0 0  0  0  2 1 0  0 4
 Record Lows Set or Tied 0 0  1  0  0 0  0  0  0  0  0  0 1
 

Temperature Ranks and Records:

 Daily Records:

 
Max:

February:  60 on the 13th (tie).
September: 91 on the 13th (tie), 89 on the 26th (tie).
October: 84 on the 10th.

Record High So Early in the Season: None
 

Min:  

March:  -17 on the 4th.

Record Lows So Early in the Season: None

 

    Warmest Months of September on Record
Rank Year Average Temperature °F
1 2015 63.7
2 1998 63.5
3 1990 63.4
4 2009, 2001 62.3
6 1938 62.2
7 1948 62.1
8 1940 62.0
 
    Warmest Months of October on Record
Rank Year Average Temperature °F
1 1963 52.0
2 2015 51.7
3 2010 50.9
4 2003 50.7
5 2014 50.4
7 1988 50.0
8 1934 49.6
 

 

   Top Ten Warmest Years on Record
Rank Year Average Temperature °F
1 2012 48.6
2 2006 47.1
3 1934 47.0
4 2007 46.5
5 2005 46.4
6 1954 46.2
7 2015 46.0
8 1953 45.9
9 2003 45.8
10 1946 45.6
 
   Top Ten Coldest Years on Record
Rank Year Average Temperature °F
1 1993 39.0
2 1924 39.6
3 1984, 1944 39.7
5 1968 40.5
6 1929 40.7
7 1932 41.0
8 1983, 1923 41.5
10 1942 41.6
85 2015 46.0
 

 

Click to enlarge Click to enlarge
 Average Annual Temperature for Period of Record - Click on Graph to Enlarge

 


 

Precipitation Banner

 

 

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
 Total (inches) 0.04 1.28 0.47 1.10 4.03 0.82 0.81 0.17 0.10 0.38 0.99 0.09 10.28
 Mean Precip (1981-2010 Normals) 0.28 0.33 0.56 0.98 1.45 1.21 0.78 0.50 0.83 0.85 0.41 0.24 8.42
 Departure from Normal -0.24 0.95 -0.09 0.12 2.58 -0.39 0.03 -0.33 -0.73 -0.47 0.58 -0.15 1.86
 Percent of Normal 14 388 84 112 278 68 104 34 12 45 241  38 122

 Rank - Driest to Wettest
 97 years (P.O.R 1918 - 2015)

20  95  59  62 89   42 64 29 13 32 91 26 78
 Greatest 24-HR Total  0.02 0.55  0.31 0.58  0.95  0.32  0.35  0.09  0.08 0.34 0.32 0.05 0.95
 Dates of Occurrence  12  16  3  26  20  16  8  4  4  3  26  15  5/20
 Number of Days with:                          
    Precipitation >= 0.01 3 6 4 6  17 6 5  4  3  3  7  3  67
    Precipitation >= 0.10 0 3 2 4  7  4  3  0  0  1  3  0 27
    Precipitation >= 1.00 0 0  0 0  0 0  0  0  0 0  0  0 0
Daily Precipitaton Records Set or Tied 0 1  0 0  1  0 0  0  0 0 0 0 2

 

 

 

 

 

 

 

 

 

 

 

 

Precipitation Ranks and Records:

One Day Precipitation Records:

February:  0.55 on the 16th
May:  0.92 on the 25th.
 
 
    Wettest Months of February on Record
Rank Year Precipitation (inches)
1 2004 1.33
2 2015 1.28
3 2003 0.97
4 1986 0.90
5 1955 0.86
6 1935 0.80
 
   Wettest Months of May on Record
Rank Year Precpitation (inches)
1 1921 6.22
2 2011 5.29
3 2008 4.75
4 1924 4.59
5 1978 4.44
6 1971 4.42
7 1908 4.28
8 1957 4.19
9 2015 4.03
10 1942 3.98
 
    Wettest Months of November on Record
Rank Year Precipitation (inches)
1 1996 2.13
2 1983 1.57
3 1942 1.36
4 1985 1.06
6 1945 1.04
7 2015, 1919 0.99
9 1972 0.97
10 1938, 1928 0.93
 

 

 

   Top Ten Driest Years on Record
Rank Year Precpitation (inches)
1 1988 3.75
2 2012 3.98
3 1974 4.12
4 1954 4.85
5 2001, 2006 5.07
7 1966 5.66
8 1990 5.71
9 1922 5.91
10 1932 6.05
78 2015 10.28
 
   Top Ten Wettest Years on Record
Rank Year Precipitation (inches)
1 1912 24.63
2 1923 18.43
3 1941 14.74
4 1993 13.49
5 1995 13.41
6 1998 13.39
7 1971 13.11
8 1997 12.67
9 1947 12.45
10 1944 12.19
22 2015 10.28

 

Click to enlarge Click to enlarge
 Annual Precipitation for Period of Record - Click on Graph to Enlarge

  

 


 

  Snow Banner

 

 

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
 Total (inches) 0.7 17.8 6.6 1.8 T 0.0 0.0 0.0 0.0 0.0 19.0 2.4 48.3
 Mean Snowfall (1981-2010 Normals) 4.8 6.0 5.9 6.1 1.2 0.0 0.0 0.0 0.3 3.7 4.3 4.8 37.1
 Departure from Normal -4.1 11.8 0.7 -4.3 -1.2 0.0 0.0 0.0 -0.3  -3.7 14.7 -2.4 11.2
 Percent of Normal 15 297 112 30 0 0 0 0 0  0 442 50 130
 Rank - Least Snowiest to Snowiest
 97 Years (P.O.R 1918-2015)
 17 92 63 38 66* NA NA NA 1^ 1# 94 31 76
 Greatest 24-HR Total 0.3 6.1 5.0 1.3  T 0.0  0.0 0.0 0.0 0.0 7.8 1.4  7.8
 Dates of Occurrence 12 16 3 16  11 NA NA NA  NA  NA  26  15  11/26
 Number of Days with:                          
    Snowfall >= 1.0 inch 0 6 2 1  0 0 0 0  0 0  6 1  16
Daily Snowfall Records Set or Tied 0 2 0 0  0 0 0 0  0 0  0  01 2

* 65 Months of May on record with no snow, 2012 and 2015 only two years with a trace of snow.
^ 80 Months of September on record with no snow.

# 40 months of October on record with no snow.

 

 

 

 

 

 

 

 

 

 

 



 

Snowfall Ranks and Records:

One Day Snowfall Records (inches):

February:  4.2 on the 4th, 6.1 on the 16th

 

   Snowiest Months of February on Record
Rank Year Snowfall (inches)
1 1987 22.5
2 2015 17.8
3 2004 16.9
4 1959 16.0
5 2003 15.3
7 1965 13.5
8 1935, 1920 13.0
10 2011 12.8
 

 

   Snowiest Months of November on Record
Rank Year Snowfall (inches)
1 1983 22.0
2 2015,1942 19.0
4 1920 17.0
5 1985 15.2
6 1978 14.8
7 1938, 1919 14.0
9 1967 13.5
10 1928 13.0
 

 

   Top Ten Snowiest Years on Record
Rank Year Snowfall (inches)
1 1920 77.0
2 2013 70.6
3 2009 62.5
4 2010 60.1
5 1919 58.0
6 1923 56.2
7 1944 55.4
8 1987 53.5
9 1972 53.4
10 1942 52.5
15 2015 48.3

 

Click to enlarge Click to enlarge
Click to enlarge
 Annual and Seasonal Snowfall for Period of Record - Click on Graph to Enlarge

  

 


 

 

 

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