National Weather Service United States Department of Commerce

Riverton Climate Summary Banner

...Highlights of 2021...

  • Annual: Average temperature 3.6 degrees above normal in 2021. Precipitation was 1.02 inches below normal, or 89% of normal. Below average snowfall of 92%,  and just 3.5 inches below normal.
    • Average annual temperature 47.1 degrees which was the 2nd warmest year on 103 years of record (1918-2021).
    • 2021 precipitation total was 8.48 inches which was the 51st driest or 53 wettest year on 103 years of record (1918-2021).
    • 2021 snowfall total was 40.8 inches which was the 33rd snowiest year on 103 years of record. .
  • Seasonal:  The 2020-2021 Seasonal Snow total was 48.2 inches, the 20th snowiest season on record.
     
  • Monthly Temperatures: 2nd warmest June, 6th warmest July, 10th warmest September, 3rd warmest November, and 2nd warmest December.
  • Monthly Precipitation: 5th wettest March, 7th wettest August, and tied for 3rd driest November
  • Monthly Snowfall: 8th snowiest March and 10th snowiest April on record.

Temperature Banner   

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
 Average High 35.4 32.4 49.7 55.4 67.6 87.5 91.6 84.8 79.3 59.9 51.3 43.9 61.6
 Mean High (1991-2020 Normals) 28.7 35.5 49.2 58 67.4 78.9 87.9 85.7 74.4 59.2 42.7 29.6 58.1
 Average Low 10.2 5.4 22.8 28.7 40.3 52.9 58 52.3 44 33.3 24.4 16.9 32.4
 Mean Low (1991-2020 Normals) 4.2 9.6 22.2 30.5 40.3 48.5 54.8 52.2 42.5 30.4 17.1 5.7 29.8
 Average Temperature 22.8 18.7 36.3 42.1 54 70.2 74.8 68.6 61.6 46.6 37.9 30.4 47.0
 Mean Average Temperature (1991-2020 Normals) 16.4 22.5 35.7 44.2 53.8 63.7 71.3 69 58.4 44.8 29.9 17.6 43.9
 Departure from Normal 6.4 -3.8 0.6 -2.1 0.2 6.5 3.5 -0.4 3.2 1.8 8 12.8 3.1
 Rank: Coldest         to          Warmest
 103 years of record
(P.O.R 12/1918-2021)
86 33 73 27 51 99 96 63 93 69 101 100 98
 Highest Daily Maximum 58 58 67 77 84 101 102 95 94 78 66 63 102
 Date of Occurrence 14 23 9 5 8,21 16 28 12,17 10 5 7 3 07/28
 Lowest Daily Minimum -5 -11 5 10 28 45 50 42 28 21 9 -2 -11
 Date of Occurrence 27 13,14 1 20 9 2 11 29 30 13 18 18 02/3,4
 Number of Days with:                          
    Maximum >= 90° 0 0 0 0 0 15 21 8 3 0 0 0 47
    Maximum <= 32° 13 13 0 0 0 0 0 0 0 0 0 6 32
    Minimum <= 32° 31 28 28 20 1 0 0 0 3 15 26 29 181
    Minimum <= 0° 1 9 0 0 0 0 0 0 0 0 0 1 11
 Record Highs Set or Tied 1 0 2 1 0 5 1 0 2 0 0 1 13
 Record Lows Set or Tied 0 1 0 0 0 0 0 0 0 0 0 0 1
 * Multiple day occurrence

Temperature Ranks and Records:

 Daily Records:

 
Max:

   January:  58 on the 14th.
   March:  64 on the 7th (tie) and 67 on the 9th.
    April:  77 on the 5th
   June:  97 on the 9th (tie), 100 on the 15th, 101 on the 16th, 100 on the 17th and 95 on the 18th (tie).           
    July: 102 on the 28th.
    September: 94 on the 10th and 90 on the 11th (tie).
    December: 63 on the 3rd.

 

Min:  

  No Record Low temperatures set in 2021.
 
 

 

   Top Ten Warmest June's on Record
Rank Year Average Temperature °F
1 1988 72.2
2 2021 70.2
3 1977 69.3
4 2016 68.9
5 2006 68.8
6 2012 68.5
7 2015 68.4
8 1933 68.2
9 2013 67.6
10 2007 67.1

 

   Top Ten Warmest July's on Record
Rank Year Average Temperature °F
1 2006 76.2
2 2012, 2007 76.1
4 2003 75.3
5 2002 74.9
6 2021, 2001 74.8
8 2013 74.4
9 1954 74.2
10 2005 74.1

 

   Top Ten Warmest September's on Record
Rank Year Average Temperature °F
1 2015 63.6
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
9 1963 61.8
10 2021 61.6

 

   Top Ten Warmest November's on Record
Rank Year Average Temperature °F
1 1949 40.0
2 1954 38.6
3 2021 37.9
4 1999 37.7
5 1927 37.0
6 2008 36.1
7 1926 36.0
8 1995 35.8
9 1965, 2016 35.7
10 2017 35.3

 

   Top Ten Warmest December's on Record
Rank Year Average Temperature °F
1 1933 31.8
2 2021 30.4
3 1950 29.2
4 1980 29.0
5 1957, 1946 27.7
7 1999 27.3
8 1939 27.2
9 1929 26.5
10 1994 26.3

 

   Warmest Years on Record (101 Years)
Rank Year Average Temperature °F
1 2012 48.5
2 2021 47.1
3 2006, 1999 47.0
5 1934 46.9
6 2007 46.5
7 2005, 1981 46.3
9 1954 46.2
10 2015 45.9
 

 

   Top Ten Coldest Years on Record
Rank Year Average Temperature °F
1 1993 38.8
2 1924 39.5
3 1984, 1944 39.7
5 1978 40.1
6 1985 40.3
7 1968, 1929 40.5
9 1975 40.8
10 1986, 1932 41.0
98 2021 47.1

 

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

  


 

Learn more about the National Weather Service's efforts to build a Weather-Ready Nation!

 

 

 
 

 

 

 

 

Precipitation Banner

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
 Total (inches) 0.14 0.22 1.24 1.37 1.23 0.46 0.18 1.16 0.55 1.82 0.03 0.08 8.48
 Mean Precipitation
(1991-2020 Normals)
0.35 0.43 0.71 1.31 1.98 1.09 0.70 0.45 0.80 0.93 0.44 0.31 9.5
 Departure from Normal -0.21 -0.21 0.53 0.06 -0.75 -0.63 -0.52 0.71 -0.25 0.89 -0.41 -0.23 -1.02
 Percent of Normal 40 51 175 105 62 42 26 258 69 196 7 26 89

 Rank - Driest            to           Wettest
 103 years (P.O.R. 1918-2021)

42 57 99 70 37 29 23 98 48 92 10 26 51
 
 Greatest 24-HR Total 0.04 0.07 0.53 0.56 0.57 0.37 0.08 0.44 0.31 0.60 0.03 0.03 0.60
 Dates of Occurrence 6,24 18 14 15 3 25 6 1 29 19 24 27 7/6
 Number of Days with:                          
    Precipitation >= 0.01 4 4 9 10 10 4 4 6 5 9 1 4 70
    Precipitation >= 0.10 0 0 2 4 3 1 0 3 2 6 0 0 21
    Precipitation >= 1.00 0 0 0 0 0 0  0 0 0 0 0 0 0
Daily Precipitation Records Set or Tied 0 0 0 1 0 0 0 0 0 0 0 0 1
                           

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Precipitation Ranks and Records:
 

One Day Precipitation Records:

   April: 0.56" on the 15th.
  


 

   Top Ten Wettest March's on Record
Rank Year Precipitation (inches)
1 1998 2.95
2 2016 2.70
3 2017 2.45
4 1941 1.52
5 2021 1.24
6 1992 1.21
7 1977 1.20
8 2009 1.15
9 1968 1.05
10 1958 1.03
 

 

   Top Ten Wettest August's on Record
Rank Year Precipitation (inches)
1 1933 3.06
2 1930 2.90
3 1976 1.56
4 1941 1.28
5 1968 1.24
6 2004 1.21
7 2021 1.16
8 2014 1.11
8 1983 1.10
10 2017 1.09
 

 

   Top Ten Driest November's on Record
Rank Year Precipitation (inches)
1 1939 0
1 1949 0
1 1976 0
1 1989 0
5 1981 0.01
5 1982 0.01
5 2009 0.01
8 1954 0.03
8 2021, 2020 0.03
10 1988 0.04
 

 

   Top Ten Driest Years on Record
Rank Year Precipitation (inches)
1 1988 3.75
2 2012 3.98
3 1974 4.12
4 1954 4.85
5 2001, 2006 5.07
7 2020 5.62
8 1966 5.66
9 1990 5.71
10 1922 5.91
51 2021 8.48

 

   Top Ten Wettest Years on Record
Rank Year Precipitation (inches)
1 1923 18.43
2 2017 15.86
3 2016 15.24
4 1941 14.74
5 1912 14.73
6 1993 13.49
7 1998, 1995 13.41
9 1971 13.11
10 1947 12.45
51 2021 8.48
 

 

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

  


 

 

Learn more about the National Weather Service's efforts to build a Weather-Ready Nation!

 

 

 
 

 

 

 

 

  Snow Banner

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
 Total (inches) 3.5 3.2 11.4 16.6 0.001 0 0 0 0 3.5 0.9 1.7 40.8
 Mean Snowfall (1991-2020 Normals) 5.5 7.4 6.5 7.2 2.1 0.0 0.0 0.0 0.6 4.4 5.3 5.3 44.3
 Departure from Normal -2 -4.2 4.9 9.4 -2.1 0.0 0.0 0.0 -0.6 -0.9 -4.4 -3.6 -3.5
 Percent of Normal 64 43 175 231 1 0 0 0 0 80 17 32 92
  Rank - Least            to           Most
 103 years (P.O.R 1918-2021)
54 47 92 92 71 NA NA NA NA 66 78 29 71
 
 Greatest 24-HR Total 1.1 1 5 11.2 T 0 0 0 0 1.8 0.9 0.5 11.2
 Dates of Occurrence 26 8 10 15 5 0 0 0 0 13 24 27 4/15
 Number of Days with:                          
    Snowfall >= 1.0 inch 1 2 2 3 0 0 0 0 0 2 0 0 19
Daily Snowfall Records Set or Tied 0 0 0 1 0 0 0 0 0 0 0 0 1

 *   69 months of May on record a trace or 0.0" of snowfall.
 *  83 months of September on record with no snowfall.

 

 

 

 

 

 

 

 

 

 

 





 

Snowfall Ranks and Records:
 

One Day Snowfall Records (inches):

  April11.2" on the 15th.
 

 

 

   Top Ten Snowiest March's on Record
Rank Year Snowfall (inches)
1 2015 22.1
2 1997 21.7
3 1967 19.5
4 1923 18.5
5 2008 15.2
6 1972 14.0
7 1940 15.0
8 2021 11.4
9 2019, 2002, 1937 11.0

 

   Top Ten Snowiest April's on Record
Rank Year Snowfall (inches)
1 1998 31.7
2 1919 29.0
3 2012 24.7
4 1944 22.1
5 1921 21.0
6 2016 20.9
7 2020 20.3
8 1926 18.0
9 1978, 1933 17.0
10 2021 16.6

 

   Top Ten Snowiest Years on Record
Rank Year Snowfall (inches)
1 1920 77.0
2 2017 71.1
3 2013 70.6
4 2009 62.5
5 2020 61.7
5 2016 61.7
7 2010 60.1
8 1919 58.0
9 1923 56.2
10 1944 55.4
35 2021 40.8

 

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

  

 


 

Learn more about the National Weather Service's efforts to build a Weather-Ready Nation!

 

 
 

 

 

 

 

 


 

Learn more about the National Weather Service's efforts to build a Weather-Ready Nation!