September
September · June · July
United States · 1991–2020
September leads for comfortable weather in Wyoming: typically 24.3°C by day, 11.7°C at night, with 108 mm of rain. Based on measured 1991–2020 NOAA station history.
September · June · July
July · August · June
May · September · October
The weakest month is January, scoring 5 against September’s 79 — days reach only 4.6°C, 19° below the 24°C the score treats as ideal, and nights drop to -6.4°C.
Month by month
The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.
| Month | Day | Night | Rain | Wet days | Sea | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|---|
| January | 4.6°C | -6.4°C | 108 mm | 9.2 | 5.9°C | 9 h 29 | 5 | Strong coverage |
| February | 5.9°C | -5.8°C | 96 mm | 8.1 | 4.1°C | 10 h 32 | 5 | Strong coverage |
| March | 9.5°C | -2.2°C | 142 mm | 9 | 4.2°C | 11 h 48 | 5 | Strong coverage |
| April | 15.4°C | 2.6°C | 124 mm | 9.8 | 6.5°C | 13 h 16 | 31 | Strong coverage |
| May | 20.9°C | 7.9°C | 97 mm | 10.2 | 10.7°C | 14 h 30 | 62 | Strong coverage |
| June | 25.5°C | 13.1°C | 104 mm | 9 | 15.6°C | 15 h 10 | 76 | Strong coverage |
| July | 28.6°C | 16.3°C | 84 mm | 7.3 | 19.6°C | 14 h 54 | 72 | Strong coverage |
| August | 28°C | 15.5°C | 108 mm | 8.1 | 20.6°C | 13 h 50 | 71 | Strong coverage |
| September | 24.3°C | 11.7°C | 108 mm | 7.7 | 19.3°C | 12 h 25 | 79 | Strong coverage |
| October | 18.4°C | 5.6°C | 127 mm | 9 | 16.4°C | 11 h 01 | 46 | Strong coverage |
| November | 12.5°C | 0.8°C | 114 mm | 8.6 | 12.6°C | 9 h 47 | 20 | Strong coverage |
| December | 7.3°C | -3.4°C | 135 mm | 9.7 | 9.0°C | 9 h 11 | 5 | Strong coverage |
What has changed
Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 20.6°C12 Jan 2020 | -30.6°C11 Jan 1942 | 100 mm7 Jan 1962 | 315 mm1979 · driest 21 mm in 1955 | 129 |
| February | 22.8°C16 Feb 2023 | -30.0°C7 Feb 1934 | 83 mm26 Feb 1960 | 240 mm1893 · driest 17 mm in 1947 | 129 |
| March | 27.8°C29 Mar 1945 | -23.3°C19 Mar 1967 | 170 mm30 Mar 2010 | 492 mm2010 · driest 6 mm in 1915 | 128 |
| April | 33.3°C14 Apr 2023 | -13.3°C1 Apr 1923 | 90 mm13 Apr 1913 | 329 mm1983 · driest 18 mm in 1942 | 129 |
| May | 36.1°C26 May 2010 | -3.9°C1 May 2000 | 125 mm16 May 2024 | 244 mm1978 · driest 10 mm in 2015 | 129 |
| June | 37.8°C24 Jun 2025 | -1.1°C1 Jun 1930 | 126 mm5 Jun 1982 | 365 mm1982 · driest 1 mm in 1949 | 129 |
| July | 37.8°C22 Jul 2011 | 3.3°C12 Jul 1945 | 117 mm24 Jul 2009 | 307 mm2009 · driest 11 mm in 1952 | 128 |
| August | 37.8°C2 Aug 1975 | 0.6°C25 Aug 1940 | 154 mm26 Aug 1924 | 323 mm1985 · driest 14 mm in 1993 | 128 |
| September | 35.0°C2 Sep 1953 | -3.9°C29 Sep 1957 | 165 mm21 Sep 1961 | 322 mm1932 · driest 9 mm in 1941 | 127 |
| October | 30.6°C17 Oct 1938 | -10.6°C28 Oct 1940 | 163 mm15 Oct 2005 | 379 mm2005 · driest 7 mm in 1924 | 128 |
| November | 26.7°C7 Nov 2022 | -20.0°C24 Nov 1989 | 131 mm2 Nov 1897 | 330 mm1983 · driest 19 mm in 1976 | 128 |
| December | 22.8°C7 Dec 1998 | -27.2°C17 Dec 1942 | 109 mm3 Dec 1986 | 294 mm1936 · driest 14 mm in 1931 | 128 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 27 | 4 | 5 |
| February | 0 | 0 | 24 | 3 | 4 |
| March | <1 | 0 | 21 | 4 | 3 |
| April | 1 | <1 | 10 | 4 | <1 |
| May | 6 | 1 | 1 | 3 | 0 |
| June | 18 | 4 | 0 | 3 | 0 |
| July | 28 | 11 | 0 | 3 | 0 |
| August | 27 | 9 | 0 | 3 | 0 |
| September | 14 | 1 | <1 | 4 | 0 |
| October | 2 | <1 | 6 | 4 | <1 |
| November | <1 | 0 | 16 | 4 | <1 |
| December | 0 | 0 | 23 | 5 | 3 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 33% | 13% | 34% | 0.6–6.5°C |
| February | <1% | 32% | 14% | 33% | 0.5–7.6°C |
| March | 2% | 33% | 14% | 34% | 5.5–11.2°C |
| April | 11% | 30% | 12% | 35% | 11.6–16.3°C |
| May | 38% | 30% | 10% | 35% | 17.5–22.0°C |
| June | 68% | 27% | 9% | 30% | 22.3–26.4°C |
| July | 76% | 24% | 8% | 22% | 25.7–29.2°C |
| August | 74% | 25% | 10% | 25% | 24.7–28.5°C |
| September | 64% | 24% | 10% | 23% | 21.4–25.2°C |
| October | 26% | 28% | 12% | 26% | 16.1–20.0°C |
| November | 3% | 31% | 14% | 32% | 9.2–14.1°C |
| December | <1% | 33% | 15% | 36% | 2.3–8.5°C |
A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.
The evidence behind this page