September
September · October · May
United States · 1991–2020
September leads for comfortable weather in Antioch: typically 28.1°C by day, 14.9°C at night, with 107 mm of rain. Based on measured 1991–2020 NOAA station history.
September · October · May
August · June · July
October · April · November
The weakest month is January, scoring 5 against September’s 75 — days reach only 9.5°C, 14° below the 24°C the score treats as ideal, and nights drop to -1.9°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 | 9.5°C | -1.9°C | 135 mm | 7.4 | 10 h 02 | 5 | Strong coverage |
| February | 12°C | -0.3°C | 147 mm | 7.3 | 10 h 51 | 13 | Strong coverage |
| March | 16.6°C | 3.4°C | 133 mm | 8.1 | 11 h 52 | 36 | Strong coverage |
| April | 21.8°C | 8°C | 136 mm | 7.7 | 13 h 01 | 62 | Strong coverage |
| May | 25.7°C | 13.3°C | 131 mm | 7.1 | 13 h 59 | 74 | Strong coverage |
| June | 29.5°C | 17.6°C | 119 mm | 7.4 | 14 h 31 | 62 | Strong coverage |
| July | 31.2°C | 19.6°C | 136 mm | 7.1 | 14 h 18 | 50 | Strong coverage |
| August | 31°C | 18.8°C | 89 mm | 5.6 | 13 h 29 | 60 | Strong coverage |
| September | 28.1°C | 14.9°C | 107 mm | 4.7 | 12 h 21 | 75 | Strong coverage |
| October | 22.5°C | 8.6°C | 88 mm | 4.5 | 11 h 14 | 75 | Strong coverage |
| November | 15.9°C | 2.8°C | 101 mm | 6.1 | 10 h 16 | 39 | Strong coverage |
| December | 10.6°C | -0.5°C | 166 mm | 7.8 | 9 h 48 | 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 | 24.4°C24 Jan 1972 | -25.6°C21 Jan 1985 | 144 mm23 Jan 2002 | 369 mm1999 · driest 0 mm in 2021 | 70 |
| February | 27.2°C23 Feb 2023 | -24.4°C17 Feb 1958 | 112 mm14 Feb 2003 | 462 mm2018 · driest 0 mm in 2021 | 71 |
| March | 29.4°C22 Mar 2026 | -15.6°C3 Mar 1980 | 194 mm21 Mar 1955 | 434 mm1973 · driest 0 mm in 2021 | 70 |
| April | 31.7°C30 Apr 1987 | -5.6°C7 Apr 2007 | 84 mm5 Apr 1983 | 320 mm2011 · driest 0 mm in 2021 | 71 |
| May | 34.4°C28 May 1962 | -1.1°C2 May 1963 | 119 mm26 May 1991 | 352 mm1983 · driest 0 mm in 2020 | 69 |
| June | 41.1°C29 Jun 2012 | 2.2°C1 Jun 1966 | 137 mm9 Jun 1997 | 303 mm1997 · driest 0 mm in 2021 | 70 |
| July | 39.4°C17 Jul 1980 | 8.3°C15 Jul 1967 | 223 mm14 Jul 1998 | 464 mm1998 · driest 0 mm in 2020 | 69 |
| August | 40.0°C15 Aug 2007 | 6.7°C6 Aug 1994 | 113 mm29 Aug 2005 | 284 mm1981 · driest 0 mm in 2024 | 68 |
| September | 37.2°C17 Sep 1965 | -0.6°C30 Sep 1967 | 119 mm18 Sep 1970 | 289 mm1977 · driest 0 mm in 2016 | 71 |
| October | 35.6°C1 Oct 2019 | -7.2°C27 Oct 1961 | 125 mm18 Oct 2004 | 284 mm1984 · driest 0 mm in 2005 | 72 |
| November | 32.2°C1 Nov 2016 | -13.3°C30 Nov 1976 | 95 mm8 Nov 1986 | 328 mm1986 · driest 0 mm in 2020 | 71 |
| December | 23.9°C25 Dec 2025 | -23.3°C22 Dec 1989 | 117 mm13 Dec 1998 | 367 mm1990 · driest 0 mm in 2020 | 70 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 21 | 4 | <1 |
| February | <1 | 0 | 16 | 4 | <1 |
| March | 3 | 0 | 10 | 5 | <1 |
| April | 10 | <1 | 2 | 4 | 0 |
| May | 20 | 5 | 0 | 4 | 0 |
| June | 27 | 15 | 0 | 4 | 0 |
| July | 30 | 23 | 0 | 4 | 0 |
| August | 30 | 21 | 0 | 3 | 0 |
| September | 24 | 11 | 0 | 3 | 0 |
| October | 12 | 1 | 2 | 3 | 0 |
| November | 1 | <1 | 11 | 3 | 0 |
| December | 0 | 0 | 18 | 5 | <1 |
The best month has moved. On the 1961–1990 numbers the strongest month here was September (scoring 76); 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 | 3% | 26% | 13% | 27% | 6.3–12.5°C |
| February | 9% | 29% | 16% | 29% | 8.9–15.5°C |
| March | 28% | 28% | 15% | 31% | 13.4–20.3°C |
| April | 54% | 26% | 13% | 27% | 19.9–24.3°C |
| May | 69% | 26% | 13% | 28% | 24.2–28.0°C |
| June | 75% | 25% | 12% | 28% | 27.7–31.3°C |
| July | 74% | 26% | 12% | 27% | 29.8–32.9°C |
| August | 80% | 20% | 9% | 19% | 29.4–32.9°C |
| September | 79% | 20% | 10% | 17% | 26.4–30.1°C |
| October | 62% | 18% | 9% | 14% | 20.8–24.6°C |
| November | 24% | 24% | 12% | 23% | 13.3–18.8°C |
| December | 4% | 27% | 15% | 30% | 8.7–13.9°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