September
September · May · October
United States · 1991–2020
September leads for comfortable weather in Fort Downer: typically 28.1°C by day, 12.8°C at night, with 48 mm of rain. Based on measured 1991–2020 NOAA station history.
September · May · October
June · August · September
October · April · May
The weakest month is January, scoring 5 against September’s 80 — days reach only 5.7°C, 18° below the 24°C the score treats as ideal, and nights drop to -7.6°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 | 5.7°C | -7.6°C | 14 mm | 2.3 | 9 h 43 | 5 | Strong coverage |
| February | 7.9°C | -6.2°C | 22 mm | 3.1 | 10 h 41 | 9 | Strong coverage |
| March | 13.9°C | -1.4°C | 34 mm | 3.9 | 11 h 50 | 36 | Strong coverage |
| April | 19°C | 3.8°C | 43 mm | 5.7 | 13 h 09 | 60 | Strong coverage |
| May | 24.4°C | 10.1°C | 98 mm | 7.9 | 14 h 16 | 77 | Strong coverage |
| June | 30.8°C | 16.3°C | 78 mm | 6.6 | 14 h 52 | 66 | Strong coverage |
| July | 33.8°C | 19.1°C | 89 mm | 6.7 | 14 h 38 | 49 | Strong coverage |
| August | 32.4°C | 17.8°C | 77 mm | 6.4 | 13 h 41 | 58 | Strong coverage |
| September | 28.1°C | 12.8°C | 48 mm | 4.5 | 12 h 24 | 80 | Strong coverage |
| October | 20.6°C | 5.2°C | 42 mm | 4.1 | 11 h 07 | 69 | Strong coverage |
| November | 12.8°C | -1.5°C | 22 mm | 2.8 | 10 h 00 | 33 | Strong coverage |
| December | 6.4°C | -6.4°C | 19 mm | 2.8 | 9 h 27 | 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 | 28.3°C28 Jan 2015 | -31.7°C12 Jan 1912 | 31 mm10 Jan 1985 | 56 mm1985 · driest 0 mm in 1976 | 122 |
| February | 30.6°C19 Feb 2016 | -28.3°C8 Feb 1933 | 38 mm27 Feb 1918 | 74 mm1918 · driest 0 mm in 1893 | 121 |
| March | 35.6°C26 Mar 2026 | -26.1°C11 Mar 1948 | 52 mm19 Mar 1984 | 179 mm1973 · driest 0 mm in 1920 | 122 |
| April | 38.9°C23 Apr 1989 | -14.4°C2 Apr 1936 | 74 mm13 Apr 1927 | 159 mm1984 · driest 0 mm in 2012 | 122 |
| May | 39.4°C23 May 1939 | -6.7°C1 May 1909 | 140 mm29 May 2018 | 308 mm1995 · driest 6 mm in 1966 | 123 |
| June | 45.6°C28 Jun 2012 | 2.8°C2 Jun 1917 | 112 mm17 Jun 1957 | 321 mm1951 · driest 5 mm in 1981 | 123 |
| July | 46.1°C24 Jul 1936 | 6.1°C4 Jul 1924 | 188 mm29 Jul 1928 | 339 mm1993 · driest 1 mm in 2003 | 121 |
| August | 44.4°C24 Aug 1943 | 4.4°C26 Aug 1910 | 127 mm24 Aug 1960 | 219 mm1925 · driest 7 mm in 1976 | 122 |
| September | 42.8°C3 Sep 1947 | -4.4°C30 Sep 1985 | 98 mm19 Sep 1995 | 176 mm1919 · driest 1 mm in 1956 | 121 |
| October | 37.2°C5 Oct 1947 | -12.2°C29 Oct 1917 | 87 mm5 Oct 1946 | 195 mm1946 · driest 0 mm in 1938 | 122 |
| November | 31.7°C9 Nov 2006 | -20.0°C28 Nov 1976 | 62 mm16 Nov 1996 | 111 mm2024 · driest 0 mm in 1954 | 122 |
| December | 27.2°C6 Dec 1939 | -31.7°C22 Dec 1989 | 68 mm5 Dec 1913 | 133 mm1913 · driest 0 mm in 1922 | 123 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 30 | <1 | 3 |
| February | <1 | 0 | 25 | <1 | 3 |
| March | 3 | <1 | 19 | 1 | 2 |
| April | 7 | 2 | 6 | 1 | <1 |
| May | 16 | 7 | <1 | 3 | <1 |
| June | 26 | 18 | 0 | 3 | 0 |
| July | 30 | 26 | 0 | 3 | 0 |
| August | 29 | 23 | 0 | 2 | 0 |
| September | 22 | 13 | <1 | 1 | 0 |
| October | 10 | 3 | 4 | 1 | <1 |
| November | 2 | <1 | 19 | <1 | 1 |
| December | 0 | 0 | 29 | <1 | 3 |
The best month has moved. On the 1961–1990 numbers the strongest month here was September (scoring 83); on 2011–2025 it is May (84). 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 | 2% | 8% | 1% | 3% | 0.7–9.5°C |
| February | 8% | 10% | 2% | 7% | 3.4–12.9°C |
| March | 24% | 13% | 3% | 10% | 8.5–17.9°C |
| April | 43% | 19% | 5% | 18% | 16.0–22.1°C |
| May | 60% | 26% | 9% | 29% | 21.5–26.3°C |
| June | 74% | 25% | 9% | 26% | 27.0–33.0°C |
| July | 79% | 21% | 9% | 19% | 31.1–35.9°C |
| August | 80% | 20% | 7% | 16% | 30.0–35.1°C |
| September | 78% | 16% | 5% | 10% | 25.1–30.6°C |
| October | 58% | 12% | 3% | 8% | 17.6–24.2°C |
| November | 19% | 9% | 3% | 6% | 9.8–16.6°C |
| December | 3% | 8% | 1% | 3% | 3.2–9.8°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