September
September · May · August
United States · 1991–2020
September leads for comfortable weather in Pleasant Hill: typically 25.7°C by day, 12.3°C at night, with 79 mm of rain. Based on measured 1991–2020 NOAA station history.
September · May · August
July · August · June
October · September · April
The weakest month is January, scoring 5 against September’s 81 — days reach only 0.5°C, 23° 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 | 0.5°C | -8.7°C | 61 mm | 5.6 | 9 h 34 | 5 | Strong coverage |
| February | 3°C | -7°C | 39 mm | 4.3 | 10 h 35 | 5 | Strong coverage |
| March | 10.2°C | -1.3°C | 66 mm | 6.8 | 11 h 49 | 17 | Strong coverage |
| April | 17.6°C | 4.5°C | 91 mm | 9.2 | 13 h 14 | 47 | Strong coverage |
| May | 23.8°C | 11°C | 113 mm | 9.6 | 14 h 25 | 75 | Strong coverage |
| June | 28.3°C | 16.2°C | 95 mm | 8.1 | 15 h 04 | 71 | Strong coverage |
| July | 29.6°C | 17.9°C | 90 mm | 7.2 | 14 h 48 | 65 | Strong coverage |
| August | 28.6°C | 16.5°C | 76 mm | 6.7 | 13 h 47 | 73 | Strong coverage |
| September | 25.7°C | 12.3°C | 79 mm | 6 | 12 h 25 | 81 | Strong coverage |
| October | 18.6°C | 6.3°C | 86 mm | 7.9 | 11 h 03 | 55 | Strong coverage |
| November | 9.8°C | -0.1°C | 66 mm | 7 | 9 h 52 | 18 | Strong coverage |
| December | 3.4°C | -5.5°C | 56 mm | 6 | 9 h 17 | 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 | 19.4°C24 Jan 1967 | -31.7°C16 Jan 2009 | 107 mm27 Jan 2004 | 209 mm1965 · driest 0 mm in 2009 | 70 |
| February | 22.8°C26 Feb 1996 | -30.0°C10 Feb 2014 | 46 mm11 Feb 2009 | 119 mm1997 · driest 0 mm in 2007 | 70 |
| March | 29.4°C29 Mar 1986 | -21.1°C4 Mar 2002 | 95 mm28 Mar 1985 | 179 mm2007 · driest 8 mm in 1958 | 71 |
| April | 32.8°C26 Apr 1986 | -13.9°C7 Apr 1982 | 56 mm27 Apr 1959 | 274 mm1957 · driest 8 mm in 1971 | 71 |
| May | 37.2°C12 May 2022 | -5.6°C10 May 1966 | 62 mm24 May 1995 | 229 mm2013 · driest 5 mm in 1992 | 71 |
| June | 38.9°C25 Jun 1988 | 2.2°C11 Jun 1972 | 96 mm25 Jun 1968 | 208 mm1993 · driest 3 mm in 1964 | 69 |
| July | 40.6°C7 Jul 2012 | 7.2°C1 Jul 1988 | 208 mm9 Jul 1951 | 229 mm1951 · driest 12 mm in 1991 | 71 |
| August | 39.4°C17 Aug 1988 | 2.8°C18 Aug 1963 | 103 mm6 Aug 2023 | 220 mm1977 · driest 15 mm in 1984 | 70 |
| September | 37.8°C2 Sep 1953 | -4.4°C23 Sep 1974 | 91 mm14 Sep 2008 | 273 mm1961 · driest 2 mm in 1979 | 70 |
| October | 33.3°C2 Oct 1953 | -8.3°C29 Oct 1952 | 144 mm3 Oct 1986 | 252 mm2009 · driest 0 mm in 1964 | 70 |
| November | 26.1°C9 Nov 2023 | -20.0°C29 Nov 1955 | 142 mm30 Nov 2008 | 192 mm1985 · driest 0 mm in 2023 | 70 |
| December | 22.2°C3 Dec 2012 | -32.2°C22 Dec 1989 | 129 mm3 Dec 1982 | 248 mm2007 · driest 3 mm in 1955 | 69 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 28 | 2 | 3 |
| February | 0 | 0 | 24 | 1 | 3 |
| March | <1 | 0 | 20 | 2 | 2 |
| April | 4 | <1 | 6 | 3 | <1 |
| May | 14 | 5 | <1 | 4 | 0 |
| June | 24 | 11 | 0 | 3 | 0 |
| July | 29 | 15 | 0 | 3 | 0 |
| August | 27 | 11 | 0 | 2 | 0 |
| September | 17 | 6 | <1 | 2 | 0 |
| October | 6 | 1 | 4 | 3 | 0 |
| November | <1 | 0 | 16 | 2 | <1 |
| December | 0 | 0 | 25 | 2 | 3 |
The best month has moved. On the 1961–1990 numbers the strongest month here was May (scoring 82); on 2011–2025 it is September (82). 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 | 0% | 19% | 4% | 16% | -3.2–3.9°C |
| February | <1% | 19% | 4% | 16% | -1.8–6.4°C |
| March | 7% | 23% | 7% | 24% | 6.1–12.6°C |
| April | 26% | 30% | 11% | 35% | 14.4–20.1°C |
| May | 56% | 29% | 11% | 35% | 20.9–26.7°C |
| June | 71% | 26% | 11% | 29% | 26.6–30.9°C |
| July | 77% | 24% | 10% | 23% | 28.0–32.3°C |
| August | 78% | 21% | 8% | 18% | 26.9–31.0°C |
| September | 73% | 21% | 8% | 21% | 23.8–27.9°C |
| October | 36% | 22% | 8% | 22% | 16.4–21.0°C |
| November | 6% | 23% | 7% | 23% | 6.4–12.7°C |
| December | <1% | 21% | 6% | 18% | -0.1–6.6°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