September
September · May · August
United States · 1991–2020
September leads for comfortable weather in Bellwood: typically 25.3°C by day, 12.5°C at night, with 63 mm of rain. Based on measured 1991–2020 NOAA station history.
September · May · August
August · July · June
October · September · May
The weakest month is January, scoring 5 against September’s 85 — days reach only 0.3°C, 24° below the 24°C the score treats as ideal.
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 | 0.3°C | -10.1°C | 16 mm | 3.1 | 9 h 30 | 5 | Strong coverage |
| February | 2.7°C | -8°C | 18 mm | 3.3 | 10 h 33 | 5 | Strong coverage |
| March | 9.9°C | -2.1°C | 35 mm | 5.3 | 11 h 48 | 21 | Strong coverage |
| April | 16.7°C | 3.9°C | 74 mm | 7.1 | 13 h 16 | 47 | Strong coverage |
| May | 22.8°C | 10.6°C | 116 mm | 9.1 | 14 h 29 | 71 | Strong coverage |
| June | 28.5°C | 16.5°C | 120 mm | 8.7 | 15 h 09 | 65 | Strong coverage |
| July | 30.6°C | 18.9°C | 88 mm | 7.1 | 14 h 53 | 60 | Strong coverage |
| August | 29.1°C | 17.6°C | 83 mm | 7.2 | 13 h 50 | 68 | Strong coverage |
| September | 25.3°C | 12.5°C | 63 mm | 5.9 | 12 h 25 | 85 | Strong coverage |
| October | 17.3°C | 5°C | 60 mm | 5.5 | 11 h 01 | 54 | Strong coverage |
| November | 8.9°C | -2.4°C | 31 mm | 3.9 | 9 h 48 | 18 | Strong coverage |
| December | 2°C | -7.9°C | 24 mm | 3.9 | 9 h 12 | 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 | 21.1°C25 Jan 1944 | -33.9°C12 Jan 1912 | 35 mm5 Jan 1932 | 97 mm1932 · driest 0 mm in 1986 | 130 |
| February | 25.0°C25 Feb 1896 | -33.9°C13 Feb 1905 | 43 mm2 Feb 2016 | 92 mm1915 · driest 0 mm in 2022 | 130 |
| March | 35.0°C21 Mar 2026 | -26.1°C2 Mar 1913 | 91 mm14 Mar 2021 | 192 mm1987 · driest 0 mm in 1994 | 130 |
| April | 37.8°C28 Apr 1910 | -15.6°C3 Apr 1975 | 74 mm9 Apr 2013 | 191 mm1978 · driest 2 mm in 1928 | 130 |
| May | 39.4°C29 May 1913 | -5.6°C1 May 1909 | 100 mm14 May 1905 | 240 mm1903 · driest 16 mm in 2006 | 131 |
| June | 42.8°C26 Jun 1936 | 1.1°C8 Jun 1894 | 131 mm18 Jun 1946 | 317 mm1967 · driest 16 mm in 1962 | 131 |
| July | 46.1°C25 Jul 1936 | 5.0°C9 Jul 1895 | 122 mm26 Jul 2017 | 274 mm1993 · driest 1 mm in 2012 | 132 |
| August | 43.9°C18 Aug 1934 | 2.8°C20 Aug 1950 | 152 mm5 Aug 1981 | 291 mm1981 · driest 3 mm in 1941 | 132 |
| September | 40.6°C6 Sep 1939 | -4.4°C29 Sep 1984 | 145 mm11 Sep 1900 | 256 mm1965 · driest 1 mm in 2024 | 132 |
| October | 35.6°C3 Oct 1938 | -14.4°C27 Oct 1925 | 84 mm16 Oct 1968 | 167 mm2013 · driest 0 mm in 1913 | 131 |
| November | 29.4°C5 Nov 1945 | -25.6°C30 Nov 1964 | 66 mm4 Nov 1922 | 127 mm1931 · driest 0 mm in 1939 | 132 |
| December | 25.6°C6 Dec 1939 | -31.7°C28 Dec 1916 | 46 mm25 Dec 2023 | 90 mm2018 · driest 0 mm in 1943 | 132 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 31 | <1 | 3 |
| February | 0 | 0 | 26 | <1 | 3 |
| March | <1 | <1 | 21 | 1 | 2 |
| April | 4 | <1 | 7 | 3 | <1 |
| May | 13 | 4 | <1 | 4 | 0 |
| June | 25 | 13 | 0 | 4 | 0 |
| July | 29 | 19 | 0 | 3 | 0 |
| August | 27 | 14 | 0 | 3 | 0 |
| September | 17 | 7 | <1 | 2 | 0 |
| October | 4 | <1 | 6 | 2 | <1 |
| November | <1 | 0 | 21 | <1 | 1 |
| December | 0 | 0 | 30 | <1 | 3 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | <1% | 9% | 1% | 4% | -4.0–5.4°C |
| February | 1% | 11% | 2% | 6% | -2.1–8.0°C |
| March | 11% | 15% | 4% | 12% | 5.3–14.1°C |
| April | 32% | 23% | 8% | 25% | 14.1–20.1°C |
| May | 55% | 29% | 11% | 33% | 20.6–25.9°C |
| June | 70% | 28% | 11% | 33% | 26.2–31.3°C |
| July | 78% | 23% | 9% | 20% | 28.8–34.3°C |
| August | 77% | 23% | 9% | 22% | 27.6–32.8°C |
| September | 72% | 20% | 7% | 19% | 22.9–28.8°C |
| October | 43% | 15% | 5% | 11% | 15.5–22.0°C |
| November | 8% | 11% | 3% | 7% | 6.2–13.9°C |
| December | <1% | 11% | 2% | 6% | -1.5–6.1°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