September
September · May · October
United States · 1991–2020
September leads for comfortable weather in West Line: typically 27°C by day, 14.2°C at night, with 112 mm of rain. Based on measured 1991–2020 NOAA station history.
September · May · October
August · July · June
October · April · March
The weakest month is January, scoring 5 against September’s 75 — days reach only 4.7°C, 19° below the 24°C the score treats as ideal, and nights drop to -6.3°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 | 4.7°C | -6.3°C | 35 mm | 4.9 | 9 h 44 | 5 | Good coverage |
| February | 8.5°C | -3.5°C | 41 mm | 4.2 | 10 h 41 | 13 | Good coverage |
| March | 13.8°C | 1.1°C | 65 mm | 6.3 | 11 h 50 | 34 | Good coverage |
| April | 19.5°C | 6.8°C | 101 mm | 8 | 13 h 09 | 57 | Good coverage |
| May | 24.5°C | 12.8°C | 148 mm | 9.6 | 14 h 15 | 73 | Good coverage |
| June | 28.9°C | 18°C | 147 mm | 8.2 | 14 h 51 | 58 | Good coverage |
| July | 31.7°C | 20.6°C | 100 mm | 7.9 | 14 h 37 | 51 | Good coverage |
| August | 31.6°C | 19.7°C | 93 mm | 6.1 | 13 h 40 | 56 | Good coverage |
| September | 27°C | 14.2°C | 112 mm | 6.8 | 12 h 23 | 75 | Good coverage |
| October | 20.7°C | 7.8°C | 79 mm | 7.2 | 11 h 07 | 66 | Good coverage |
| November | 12.5°C | 1.5°C | 65 mm | 5.4 | 10 h 01 | 31 | Good coverage |
| December | 6.3°C | -4.2°C | 45 mm | 4.7 | 9 h 29 | 5 | Good coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 23.3°C9 Jan 2003 | -26.7°C12 Jan 1974 | 49 mm5 Jan 2005 | 134 mm1907 · driest 0 mm in 1986 | 58 |
| February | 27.8°C29 Feb 1972 | -30.0°C17 Feb 1903 | 69 mm21 Feb 1997 | 104 mm2001 · driest 0 mm in 2006 | 57 |
| March | 34.4°C22 Mar 1907 | -21.7°C4 Mar 1978 | 102 mm5 Mar 2004 | 233 mm1973 · driest 14 mm in 1995 | 56 |
| April | 33.3°C12 Apr 1972 | -10.0°C3 Apr 1975 | 80 mm27 Apr 2009 | 237 mm1994 · driest 21 mm in 2000 | 58 |
| May | 35.6°C20 May 2006 | -4.4°C6 May 1944 | 107 mm24 May 1991 | 316 mm1995 · driest 27 mm in 1965 | 58 |
| June | 41.1°C27 Jun 1980 | 5.6°C1 Jun 1982 | 151 mm21 Jun 1984 | 379 mm1981 · driest 38 mm in 1968 | 58 |
| July | 43.9°C15 Jul 1980 | 8.3°C5 Jul 1972 | 118 mm22 Jul 1993 | 372 mm1993 · driest 12 mm in 1983 | 57 |
| August | 42.8°C29 Aug 1984 | 7.2°C29 Aug 1988 | 122 mm2 Aug 1994 | 259 mm1985 · driest 6 mm in 2000 | 60 |
| September | 41.1°C2 Sep 2000 | -2.2°C23 Sep 1983 | 202 mm4 Sep 1961 | 413 mm1961 · driest 18 mm in 1991 | 58 |
| October | 35.6°C3 Oct 2000 | -7.2°C31 Oct 1993 | 98 mm11 Oct 1973 | 249 mm1969 · driest 0 mm in 1895 | 59 |
| November | 30.6°C18 Nov 1908 | -16.1°C29 Nov 1896 | 96 mm15 Nov 1964 | 207 mm1992 · driest 0 mm in 1989 | 58 |
| December | 22.2°C7 Dec 1966 | -29.4°C23 Dec 1989 | 74 mm18 Dec 1895 | 183 mm1895 · driest 0 mm in 1979 | 57 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 27 | <1 | 3 |
| February | 0 | 0 | 21 | 1 | 2 |
| March | 1 | 0 | 14 | 2 | <1 |
| April | 6 | <1 | 4 | 3 | <1 |
| May | 16 | 4 | <1 | 4 | 0 |
| June | 26 | 13 | 0 | 4 | 0 |
| July | 30 | 23 | 0 | 3 | 0 |
| August | 30 | 22 | 0 | 3 | 0 |
| September | 21 | 9 | <1 | 3 | 0 |
| October | 9 | 1 | 3 | 3 | <1 |
| November | <1 | 0 | 14 | 3 | <1 |
| December | 0 | 0 | 25 | 2 | 2 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | <1% | 15% | 4% | 11% | 1.6–8.8°C |
| February | 4% | 16% | 4% | 11% | 3.8–11.4°C |
| March | 21% | 20% | 8% | 19% | 11.0–17.1°C |
| April | 44% | 27% | 11% | 30% | 17.1–22.5°C |
| May | 61% | 31% | 13% | 38% | 22.7–27.3°C |
| June | 70% | 30% | 15% | 34% | 27.7–31.0°C |
| July | 77% | 22% | 10% | 20% | 30.2–34.0°C |
| August | 78% | 21% | 10% | 20% | 29.3–33.8°C |
| September | 74% | 23% | 10% | 23% | 24.8–30.1°C |
| October | 52% | 20% | 9% | 21% | 18.7–23.0°C |
| November | 15% | 16% | 7% | 12% | 9.4–15.5°C |
| December | 1% | 14% | 5% | 9% | 2.3–9.0°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