September
September · August · June
83climate match
United States · 1991–2020
Best time to visit
Antioch.
September leads for comfortable weather in Antioch: typically 24.9°C by day, 11.4°C at night, with 69 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high24.9°C
Typical low11.4°C
Rain in September69 mm
July
July · August · June
70climate match
October
October · September · May
75climate match
The weakest month is January, scoring 5 against September’s 83 — days reach only 1.1°C, 23° below the 24°C the score treats as ideal.
Month by month
The whole year,
without the guesswork.
The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.
Jan
51.1° / -8.1°
Feb
53.3° / -6.9°
Mar
109.1° / -2.3°
Apr
3916.3° / 3.3°
May
6822.2° / 9.8°
Jun
7326.9° / 15.2°
Jul
6628.8° / 16.8°
Aug
7527.8° / 15.5°
Sep
8324.9° / 11.4°
Oct
5518.3° / 5.5°
Nov
1810.4° / -0.3°
Dec
53.9° / -4.7°
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 1.1°C | -8.1°C | 61 mm | 7.8 | 9 h 35 | 5 | Strong coverage |
| February | 3.3°C | -6.9°C | 59 mm | 6.8 | 10 h 36 | 5 | Strong coverage |
| March | 9.1°C | -2.3°C | 73 mm | 7.8 | 11 h 49 | 10 | Strong coverage |
| April | 16.3°C | 3.3°C | 96 mm | 9.7 | 13 h 13 | 39 | Strong coverage |
| May | 22.2°C | 9.8°C | 108 mm | 10 | 14 h 24 | 68 | Strong coverage |
| June | 26.9°C | 15.2°C | 113 mm | 9.2 | 15 h 02 | 73 | Strong coverage |
| July | 28.8°C | 16.8°C | 110 mm | 7.5 | 14 h 47 | 66 | Strong coverage |
| August | 27.8°C | 15.5°C | 94 mm | 6.4 | 13 h 46 | 75 | Strong coverage |
| September | 24.9°C | 11.4°C | 69 mm | 6.2 | 12 h 25 | 83 | Strong coverage |
| October | 18.3°C | 5.5°C | 72 mm | 7.5 | 11 h 03 | 55 | Strong coverage |
| November | 10.4°C | -0.3°C | 78 mm | 7.2 | 9 h 53 | 18 | Strong coverage |
| December | 3.9°C | -4.7°C | 62 mm | 7.6 | 9 h 18 | 5 | Strong coverage |
What has changed
Antioch runs +0.7°C
on the 1961–1990 baseline.
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.
Jan—
Feb—
Mar
+1.3
Apr
+0.4
May
+1.0
Jun
+0.4
Jul
-0.4
Aug
-0.1
Sep
+0.4
Oct
+1.8
Nov
+0.3
Dec
+2.3
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 18.3°C8 Jan 2008 | -33.9°C20 Jan 1985 | 69 mm13 Jan 2013 | 148 mm2007 · driest 13 mm in 1981 | 49 |
| February | 22.8°C26 Feb 2000 | -26.7°C3 Feb 1985 | 69 mm28 Feb 2011 | 205 mm2011 · driest 2 mm in 1987 | 48 |
| March | 29.4°C22 Mar 2012 | -25.0°C9 Mar 1984 | 58 mm28 Mar 2016 | 149 mm2020 · driest 11 mm in 1994 | 52 |
| April | 30.6°C27 Apr 1986 | -12.2°C7 Apr 1982 | 83 mm11 Apr 2013 | 197 mm2024 · driest 25 mm in 2012 | 49 |
| May | 33.3°C28 May 2012 | -3.3°C8 May 2020 | 75 mm26 May 1989 | 217 mm2017 · driest 16 mm in 1988 | 48 |
| June | 40.0°C29 Jun 2012 | 3.3°C11 Jun 1980 | 93 mm27 Jun 2015 | 348 mm2015 · driest 9 mm in 2012 | 51 |
| July | 38.9°C7 Jul 2012 | 4.4°C8 Jul 1964 | 109 mm14 Jul 2015 | 286 mm2015 · driest 13 mm in 2020 | 52 |
| August | 37.8°C18 Aug 1988 | 3.3°C14 Aug 1964 | 102 mm5 Aug 1998 | 199 mm1979 · driest 17 mm in 2009 | 50 |
| September | 35.6°C11 Sep 1983 | -2.2°C23 Sep 1995 | 75 mm7 Sep 2020 | 191 mm2003 · driest 9 mm in 2007 | 49 |
| October | 32.8°C3 Oct 2014 | -8.3°C28 Oct 1976 | 74 mm25 Oct 2021 | 205 mm2021 · driest 2 mm in 2024 | 51 |
| November | 26.1°C2 Nov 2016 | -16.1°C12 Nov 2019 | 51 mm25 Nov 2010 | 194 mm1985 · driest 7 mm in 1976 | 48 |
| December | 22.2°C3 Dec 1982 | -29.4°C22 Dec 1989 | 79 mm22 Dec 2013 | 172 mm1990 · driest 11 mm in 1976 | 50 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 27 | 2 | 4 |
| February | 0 | 0 | 24 | 2 | 3 |
| March | <1 | 0 | 20 | 3 | 1 |
| April | 3 | 0 | 8 | 3 | <1 |
| May | 11 | 2 | <1 | 4 | 0 |
| June | 20 | 8 | 0 | 4 | 0 |
| July | 27 | 12 | 0 | 3 | 0 |
| August | 24 | 8 | 0 | 3 | 0 |
| September | 15 | 4 | <1 | 2 | 0 |
| October | 5 | <1 | 5 | 2 | <1 |
| November | <1 | 0 | 17 | 3 | <1 |
| December | 0 | 0 | 24 | 2 | 2 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 26% | 6% | 25% | -2.8–4.4°C |
| February | <1% | 24% | 6% | 22% | -1.5–6.3°C |
| March | 6% | 28% | 8% | 33% | 5.5–13.0°C |
| April | 20% | 34% | 11% | 47% | 13.9–18.6°C |
| May | 46% | 32% | 12% | 40% | 19.4–25.2°C |
| June | 67% | 28% | 12% | 32% | 25.0–28.7°C |
| July | 74% | 26% | 11% | 27% | 27.2–31.3°C |
| August | 77% | 22% | 10% | 20% | 26.3–29.4°C |
| September | 68% | 21% | 8% | 19% | 22.8–27.1°C |
| October | 32% | 23% | 8% | 26% | 15.9–20.0°C |
| November | 7% | 26% | 9% | 26% | 7.0–13.6°C |
| December | <1% | 26% | 6% | 29% | 0.2–7.5°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
Nearby, measured,
and named.
- Place identity
- GeoNames 4917631
- NOAA station
- USC00127069 · PORTLAND 1 SW
- Station distance
- 7 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 26 usable years
- Daylight
- Calculated from latitude 40.37°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Important limit
- Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.