Western and Central Wyoming

Weather Forecast Office

Casper 2021 Annual Summary

...Highlights of 2021...

Annual:
- 26th warmest year on record at 46.3 degrees, just 0.7 degrees above normal.
- 17th wettest year with 14.52 inches, 119% of normal.
- 7th snowiest year with 108.1 inches, 151% of normal.
- Highest wind gust was 90 mph on March 29th.
Monthly Temperatures: 2nd coldest February on record. 4th warmest June (tie), 4th warmest November and 8th warmest December on record.
Monthly Precipitation: 1st wettest March, 8th driest May and 4th wettest October on record.
Monthly Snowfall: 1st snowiest March and 4th snowiest October on record.

Temperature

Precipitation

Snow

Winds

Temperature Banner

Element	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Average High	37.3	34.3	46.6	52.2	63.4	80.6	92.3	88.5	79.9	63.3	39	33.2	59.2
Mean High (1991-2020 Normals)	35.2	37.8	48.8	56.3	66.8	79.6	89	86.7	75.6	59.7	45.9	34.7	59.7
Average Low	16.1	10.6	19.5	23.1	33.2	44.2	52.8	52.6	44.6	30.3	16.1	12.3	29.6
Mean Low (1991-2020 Normals)	15	15.4	22.7	28.2	37.1	45.4	53	51.4	42.2	30.9	22	14.8	31.5
Average Temperature	26.7	22.5	33	37.6	48.3	62.4	72.5	70.6	62.3	46.8	27.6	22.8	44.4
Mean Average Temperature (1991-2020 Normals)	25.1	26.6	35.8	42.3	52	62.5	71	69	58.9	45.3	34	24.8	45.6
Departure from Normal	1.6	-4.1	-2.8	-4.7	-3.7	-0.1	1.5	1.6	3.4	1.5	-6.4	-2	-1.2
Rank: 83 years of record (P.O.R 12/1939-2022)	57	21	34	5	8	41	60	58	73	42	7	20	20

Highest Daily Maximum	53	54	73	76	84	97	99	101	100	76	63	51	101
Date of Occurrence	17	10	28	7	27	17	9,13	10	4	20	1,2	11	8/10
Lowest Daily Minimum	-12	-4	-25	7	22	33	43	43	32	15	-11	-42	-42
Date of Occurrence	6	2,22	10	13	22	16	1	29	25	27	17	22	12/22
Number of Days with:	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Maximum >= 90°	0	0	0	0	0	6	23	12	7	0	0	0	48
Maximum <= 32°	9	11	7	2	0	0	0	0	0	0	8	11	48
Minimum <= 32°	30	28	26	28	16	0	0	0	1	22	29	30	210
Minimum <= 0°	3	8	4	0	0	0	0	0	0	0	2	6	23
Record High Temperatures Set or Tied	0	0	1	0	0	1	1	1	3	0	0	0	7
Record Low Temperatures Set or Tied	0	1	3	1	2	1	0	0	0	0	2	1	11

Temperature Ranks and Records:

Daily Records:

Record High Temperatures:

March: 64 on the 2nd (tie).

June: 97 on the 17th.

July: 99 on the 9th (tie).

  August: 101 on the 10th.
  September: 100 on the 4th (new monthly record high), 96 on the 6th (tie), and 96 on the 7th.

Record Low Temperatures:

February: -14 on the 22nd.
March: -10 on the 7th, -22 on the 9th, and -25 on the 10th (new monthly record low).

April: 7 on the 13th (tie)
   May: 22 on the 22nd and 26 on the 24th.

June: 33 on the 16th.

November: -11 on the 17th and -9 on the 18th.

December: -43 on the 22nd (new monthly record low and All-Time low for the year)

Coldest Months of April on Record
Rank	Year	Average Temperature °F
1	1997	34.9
2	1945	34.9
3	1973	36.1
4	2013	36.3
5	2022	37.6
6	1975	37.7
7	1951	37.9
8	1983	38.0
9	1970	38.2
10	1968	38.3

Coldest Months of May on Record
Rank	Year	Average Temperature °F
1	2019	46.1
2	1950	46.2
3	2010	46.5
4	1946	47.2
5	2011	47.6
6	1968	48.1
7	1943	48.2
8	2022/1995	48.3
10	1983	48.4

Coldest Months of November on Record
Rank	Year	Average Temperature °F
1	1985	20.2
2	2000	21.2
3	1955	26.0
4	1947	26.1
5	1979	26.5
6	1978	26.9
7	2022	27.6
8	1940	27.8
9	1952	28.1
10	2014	28.6

Warmest Months of September on Record
Rank	Year	Average Temperature °F
1	1998	64.7
2	2015	64.4
3	1940	64.3
4	1963	64.1
5	1969/1990/1952	63.2
6	1948	63.1
7	1994	62.8
8	1954	62.5
9	2022	62.3
10	1966	62.2

Top Ten Warmest Years on Record
Rank	Year	Average Temperature °F
1	1994	49.1
2	2012	48.7
3	1954	48.3
4	1981	48.1
5	1992	48.0
6	1940, 1953, 1963	47.3
9	2015, 2006, 1999	47.1
64	2022	44.4

Top Ten Coldest Years on Record
Rank	Year	Average Temperature °F
1	1985	42.5
2	1951	43.1
3	1978	43.2
4	1964	43.5
5	2019, 1975	43.6
6	2009, 1979, 1968, 1949	43.8
10	1971	43.9
20	2022	44.4


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

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Precipitation Banner

Element	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Total (inches)	0.90	0.85	1.54	1.98	2.61	0.21	0.31	1.99	0.81	0.27	1.15	0.74	13.36
Mean Precipitation (1991-2020 Normals)	0.49	0.56	0.84	1.41	2.21	1.34	1.19	0.79	0.95	1.19	0.64	0.61	12.22
Departure from Normal	0.41	0.29	0.7	0.57	0.4	-1.13	-0.88	1.2	-0.14	-0.92	0.51	0.13	1.14
Percent of Normal	184	152	183	140	118	16	26	252	85	23	180	121	109
Rank - 83 years (P.O.R 12/1939-2022)	75	73	72	67	55	7	11	79	47	12	71	65	60

Greatest 24-HR Total	0.44	0.26	0.53	0.99	1.2	0.2	0.88	1.06	0.33	0.18	0.32	0.38	1.2
Dates of Occurrence	21	15-16	5-6	22-23	29-30	2-3	1	11-12	9	23	3	12-13	5/29-30
Number of Days with:
Precipitation >= 0.01	8	10	10	9	11	3	2	8	8	5	11	6	91
Precipitation >= 0.10	2	3	6	7	7	1	1	6	2	1	4	3	43
Precipitation >= 1.00	0	0	0	0	0	0	0	0	0	0	0	0	0
Days with Thunderstorms	0	0	0	0	3	5	9	9	6	2	0	0	34
Daily Precipitation Records Set or Tied	1	1	0	1	0	0	0	1	0	0	0	1	5

Precipitation Ranks and Records:

One Day Precipitation Records:

January: 0.44" on the 21st.

February: 0.25" on the 16th.

April: 0.64" on the 23rd.

August: 0.68 on the 11th.

December: 0.37" on the 13th.

Top Ten Driest June's on Record
Rank	Year	Precipitation (inches)
1	1956	0.03
2	1942	0.09
3	1980	0.10
4	1940/1971	0.17
5	1977	0.19
6	2022	0.21
7	1994	0.22
8	1988	0.28
9	2012	0.28

Top Ten Driest July's on Record
Rank	Year	Precipitation (inches)
1	2020	0.02
2	1991	0.09
3	1971	0.11
4	2000	0.22
5	1999/2016	0.24
6	1955/1959	0.27
7	1989	0.28
8	1943	0.29
9	2022	0.31

Top Ten Driest October's on Record
Rank	Year	Precipitation (inches)
1	1965	0
2	1958	0.02
3	1988	0.12
4	1953/2016	0.16
5	1992	0.22
6	1964	0.23
7	1940	0.24
8	1999	0.25
9	1945/1960/2022	0.27
10	1956	0.28

Top Ten Wettest January's on Record
Rank	Year	Precipitation (inches)
1	1987	1.42
2	1949	1.36
3	1944	1.30
4	1984	1.19
5	2009	1.08
6	2016	0.99
7	1972	0.99
8	1996	0.94
9	2022	0.90
10	1962	0.85

Top Ten Wettest February's on Record
Rank	Year	Precipitation (inches)
1	1987	1.42
2	1989	1.37
3	1955	1.01
4	1993/1953	1.00
5	1995	0.95
6	1986/1976	0.89
7	2012	0.88
8	2011	0.86
9	2022/1960	0.85
10	2020	0.82

Top Ten Wettest August's on Record
Rank	Year	Precipitation (inches)
1	1941	2.79
2	1979	2.66
3	2007	2.57
4	2005	2.24
5	2022	1.99
6	1990	1.89
7	1987	1.80
8	2003	1.69
9	1972	1.52
10	2006	1.45

Top Ten Driest Years on Record
Rank	Year	Precipitation (inches)
1	2020	5.79
2	1988	6.56
3	2001	6.76
4	2002	7.05
5	1960	7.34
6	1954	7.70
7	2012	7.88
8	1963	7.90
9	1966	8.14
10	1943	8.91
60	2022	13.36

Top Ten Wettest Years on Record
Rank	Year	Precipitation (inches)
1	1982	20.48
2	1995	18.94
3	1983	18.41
4	1978	17.64
5	1941	16.24
6	1957	16.12
7	1986	15.92
8	1993	15.91
9	2009	15.77
10	2016	15.57
24	2022	13.36


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

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Snow Banner

Element	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Total (inches)	14.9	13.3	20.7	18.5	0.7	0	0	0	0	0.10	17.8	14.7	100.7
Mean Snowfall (1991-2020 Normals)	9	10.9	10.3	10.5	2.6	0.1	0	0	1.5	7	8.9	11	71.8
Departure from Normal	5.9	2.4	10.4	8	-1.9	-0.1	0.0	0.0	-1.5	-6.9	8.9	3.7	28.9
Percent of Normal	166	122	201	176	27	0	0	0	0	1	200	134	140
Rank - Least to Most 83 years (P.O.R 12/1939-2022)	73	63	72	68	37	72	NA	NA	52	11	75	68	72

Greatest 24-HR Total	7.7	4.4	6.1	6.8	0.5	0	0	0	0	0.1	4.4	9.2	9.2
Dates of Occurrence	20-21	16	5	23	19	NA	NA	NA	NA	24	17	13	12/13
Number of Days with:
Snowfall >= 1.0 inch	2	3	7	5	0	0	0	0	0	0	5	3	25
Daily Snowfall Records Set or Tied	1	2	1	1	0	0	0	0	0	0	1	1	7
* 50 months of September on record with no snowfall.

Snowfall Ranks and Records:

One Day Snowfall Records (inches):

January: 6.8" on the 21st

February: 4.1" on the 11th and 4.4" on the 16th

March: 6.1" on the 5th

April: 6.8" on the 23rd

November: 4.4" on the 17th

December: 9.2" on the 13th

Snowiest Months of January on Record
Rank	Year	Snowfall (inches)
1	1949	39.3
2	1987	24.0
3	1980	22.1
4	1984	19.4
5	1972	19.2
6	1965	16.5
7	2009	16.4
8	1979	16.3
9	1996,1962	16.2
10	2022	14.9

Snowiest Months of November on Record
Rank	Year	Snowfall (inches)
1	1983	37.1
2	1985	28.3
3	1947	25.8
4	1994	22.4
5	1956	19.9
6	1942	19.2
7	2019	18.8
8	1977	18.2
9	2022	17.8
10	1960	17.3

Top Ten Snowiest Years on Record
Rank	Year	Snowfall (inches)
1	1982	137.6
2	1975	124.0
3	1984	121.2
4	1973	118.3
5	1983	114.2
6	1978	112.7
7	2021	108.1
8	2013	107.5
9	1955	103.3
10	1979	103.0
12	2022	100.7



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

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Wind Banner

Element	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Average Speed (MPH)	16.8	15.4	12.7	11.9	10.6	10.3	8.8	7.7	9.2	10	14	16.7	12.0
Maximum 3-sec Gust	60	53	48	69	57	64	52	52	64	50	64	75	75
Direction	200	240	220	250	240	230	290	50	180	220	250	210	210
Date of Occurrence	7	19	15	4	13	20	1	24	13	22	5	27	12/27
Number of Days with:
2-Min Wind >50 mph	0	0	0	0	0	0	0	0	0	0	0	1	1
Peak Wind >50 mph	6	1	0	5	2	6	2	2	2	1	5	4	36
Peak Wind >70 mph	0	0	0	0	0	0	0	0	0	0	0	1	1

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