September
September · June · August
United States · 1991–2020
September leads for comfortable weather in Sundance: typically 23.1°C by day, 7.3°C at night, with 33 mm of rain. Based on measured 1991–2020 NOAA station history.
September · June · August
August · July · September
September · June · May
The weakest month is January, scoring 5 against September’s 82 — days reach only 1.7°C, 22° below the 24°C the score treats as ideal, and nights drop to -10.4°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 | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 1.7°C | -10.4°C | 21 mm | 5.3 | 9 h 11 | 5 | Strong coverage |
| February | 2.4°C | -10.3°C | 23 mm | 5.4 | 10 h 22 | 5 | Strong coverage |
| March | 8.1°C | -5.4°C | 27 mm | 5.9 | 11 h 46 | 8 | Strong coverage |
| April | 12.7°C | -1.4°C | 63 mm | 8.9 | 13 h 24 | 24 | Strong coverage |
| May | 18.4°C | 4.3°C | 83 mm | 10.4 | 14 h 46 | 49 | Strong coverage |
| June | 24.3°C | 9.6°C | 77 mm | 9.2 | 15 h 31 | 78 | Strong coverage |
| July | 29.2°C | 13.3°C | 63 mm | 7.3 | 15 h 13 | 72 | Strong coverage |
| August | 28.5°C | 12.5°C | 43 mm | 5.2 | 14 h 02 | 78 | Strong coverage |
| September | 23.1°C | 7.3°C | 33 mm | 4.6 | 12 h 28 | 82 | Strong coverage |
| October | 14.5°C | 0.5°C | 44 mm | 6.1 | 10 h 54 | 38 | Strong coverage |
| November | 6.7°C | -5.5°C | 24 mm | 5 | 9 h 32 | 5 | Strong coverage |
| December | 2°C | -9.8°C | 16 mm | 4.4 | 8 h 51 | 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 | 18.3°C23 Jan 1981 | -39.4°C12 Jan 1916 | 29 mm5 Jan 1949 | 64 mm1926 · driest 0 mm in 1961 | 109 |
| February | 18.9°C26 Feb 1932 | -41.1°C8 Feb 1936 | 28 mm2 Feb 1912 | 63 mm2003 · driest 0 mm in 1983 | 109 |
| March | 25.0°C28 Mar 2015 | -31.1°C3 Mar 2019 | 41 mm14 Mar 1929 | 111 mm1896 · driest 4 mm in 1981 | 109 |
| April | 30.0°C24 Apr 2012 | -23.9°C3 Apr 1945 | 46 mm6 Apr 1997 | 133 mm1941 · driest 6 mm in 1952 | 107 |
| May | 38.3°C28 May 1934 | -13.9°C12 May 1943 | 66 mm8 May 1995 | 248 mm1962 · driest 3 mm in 1936 | 111 |
| June | 38.9°C26 Jun 2012 | -3.9°C2 Jun 1919 | 69 mm3 Jun 1940 | 208 mm1964 · driest 12 mm in 1987 | 108 |
| July | 40.6°C5 Jul 1936 | -1.1°C10 Jul 1993 | 63 mm5 Jul 2012 | 146 mm1922 · driest 5 mm in 1917 | 111 |
| August | 38.9°C29 Aug 2012 | -1.1°C28 Aug 1911 | 71 mm21 Aug 1964 | 153 mm1964 · driest 0 mm in 2001 | 112 |
| September | 37.2°C12 Sep 1919 | -14.4°C25 Sep 1926 | 58 mm23 Sep 2017 | 131 mm1986 · driest 0 mm in 2012 | 112 |
| October | 33.9°C3 Oct 1992 | -27.2°C27 Oct 1925 | 83 mm6 Oct 1994 | 155 mm1998 · driest 0 mm in 1999 | 108 |
| November | 25.0°C7 Nov 1917 | -30.6°C16 Nov 1959 | 48 mm1 Nov 2000 | 111 mm2000 · driest 0 mm in 1963 | 108 |
| December | 18.3°C15 Dec 1923 | -40.0°C24 Dec 1983 | 20 mm13 Dec 1916 | 92 mm1916 · driest 0 mm in 1896 | 106 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 30 | <1 | 9 |
| February | 0 | 0 | 27 | <1 | 8 |
| March | <1 | 0 | 26 | <1 | 6 |
| April | 1 | 0 | 18 | 2 | 5 |
| May | 5 | <1 | 6 | 3 | <1 |
| June | 13 | 4 | <1 | 3 | 0 |
| July | 24 | 13 | <1 | 2 | 0 |
| August | 23 | 12 | 0 | 2 | 0 |
| September | 12 | 4 | 2 | <1 | <1 |
| October | 2 | <1 | 14 | 1 | 3 |
| November | 0 | 0 | 25 | <1 | 6 |
| December | 0 | 0 | 29 | <1 | 7 |
The best month has moved. On the 1961–1990 numbers the strongest month here was June (scoring 82); on 2011–2025 it is September (85). Both are scored the same way, from the same station — only the climate underneath changed.
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 16% | <1% | 14% | -4.1–3.5°C |
| February | 0% | 17% | 1% | 14% | -2.7–5.2°C |
| March | 2% | 19% | 2% | 17% | 2.0–10.0°C |
| April | 14% | 26% | 5% | 29% | 9.0–16.1°C |
| May | 35% | 31% | 7% | 39% | 15.0–21.1°C |
| June | 59% | 30% | 9% | 35% | 20.5–26.9°C |
| July | 76% | 22% | 6% | 20% | 25.9–31.2°C |
| August | 81% | 16% | 4% | 11% | 25.4–30.2°C |
| September | 63% | 16% | 4% | 13% | 19.1–25.4°C |
| October | 27% | 17% | 3% | 14% | 10.7–18.2°C |
| November | 1% | 16% | 1% | 12% | 3.1–9.5°C |
| December | 0% | 16% | <1% | 14% | -2.0–4.2°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