August
August · June · July
United States · 1991–2020
August leads for comfortable weather in Chester: typically 25.7°C by day, 12.5°C at night, with 113 mm of rain. Based on measured 1991–2020 NOAA station history.
August · June · July
July · August · June
September · May · June
The weakest month is January, scoring 5 against August’s 74 — days reach only -0.2°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 | -0.2°C | -10.9°C | 102 mm | 11 | 9 h 24 | 5 | Strong coverage |
| February | 1.6°C | -10.4°C | 94 mm | 9 | 10 h 30 | 5 | Strong coverage |
| March | 6°C | -6.1°C | 104 mm | 9.4 | 11 h 48 | 5 | Strong coverage |
| April | 13°C | -0.2°C | 109 mm | 10.5 | 13 h 18 | 19 | Strong coverage |
| May | 19.2°C | 5.9°C | 110 mm | 11.5 | 14 h 34 | 50 | Strong coverage |
| June | 23.7°C | 11.1°C | 135 mm | 10.3 | 15 h 15 | 72 | Strong coverage |
| July | 26.5°C | 13.7°C | 120 mm | 10.3 | 14 h 59 | 71 | Strong coverage |
| August | 25.7°C | 12.5°C | 113 mm | 8.6 | 13 h 53 | 74 | Strong coverage |
| September | 22°C | 8.6°C | 124 mm | 8.2 | 12 h 26 | 65 | Strong coverage |
| October | 15.1°C | 2.6°C | 148 mm | 9.9 | 10 h 59 | 26 | Strong coverage |
| November | 8.4°C | -2.6°C | 102 mm | 9 | 9 h 43 | 5 | Strong coverage |
| December | 2.5°C | -7.2°C | 127 mm | 10.5 | 9 h 06 | 5 | Strong coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 18.3°C7 Jan 2007 | -26.7°C31 Jan 2019 | 51 mm13 Jan 2018 | 227 mm1996 · driest 35 mm in 2002 | 26 |
| February | 22.8°C22 Feb 2018 | -28.3°C14 Feb 2016 | 74 mm25 Feb 2016 | 290 mm2008 · driest 22 mm in 2012 | 26 |
| March | 27.2°C31 Mar 1998 | -25.0°C7 Mar 2003 | 72 mm7 Mar 2011 | 215 mm2001 · driest 19 mm in 2006 | 26 |
| April | 31.7°C18 Apr 2002 | -13.3°C6 Apr 2016 | 96 mm16 Apr 2007 | 215 mm2007 · driest 30 mm in 1999 | 26 |
| May | 32.8°C27 May 2010 | -5.6°C7 May 2001 | 76 mm13 May 2006 | 207 mm2006 · driest 18 mm in 2015 | 26 |
| June | 33.9°C19 Jun 1994 | 0.0°C1 Jun 2001 | 88 mm7 Jun 2000 | 277 mm2013 · driest 20 mm in 1997 | 27 |
| July | 34.4°C8 Jul 2010 | 5.0°C3 Jul 2001 | 101 mm26 Jul 2018 | 248 mm2014 · driest 37 mm in 2005 | 27 |
| August | 33.9°C10 Aug 2001 | 3.3°C20 Aug 1995 | 93 mm29 Aug 2011 | 312 mm2011 · driest 29 mm in 1998 | 27 |
| September | 32.8°C10 Sep 2002 | -1.7°C29 Sep 1995 | 107 mm17 Sep 1999 | 358 mm2011 · driest 39 mm in 2014 | 26 |
| October | 28.9°C6 Oct 2007 | -8.9°C31 Oct 2020 | 221 mm9 Oct 2005 | 447 mm2005 · driest 24 mm in 2001 | 27 |
| November | 24.4°C5 Nov 1994 | -20.0°C23 Nov 2018 | 77 mm3 Nov 2018 | 244 mm2018 · driest 12 mm in 2012 | 26 |
| December | 20.6°C8 Dec 1998 | -22.8°C17 Dec 2013 | 84 mm12 Dec 2008 | 236 mm2008 · driest 45 mm in 1998 | 26 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 30 | 3 | 13 |
| February | 0 | 0 | 28 | 3 | 11 |
| March | <1 | 0 | 28 | 4 | 9 |
| April | 1 | <1 | 18 | 4 | 3 |
| May | 6 | <1 | 3 | 4 | <1 |
| June | 13 | 3 | 0 | 4 | 0 |
| July | 23 | 5 | 0 | 4 | 0 |
| August | 20 | 3 | 0 | 4 | 0 |
| September | 8 | 1 | <1 | 4 | 0 |
| October | <1 | 0 | 11 | 4 | <1 |
| November | 0 | 0 | 22 | 3 | 4 |
| December | 0 | 0 | 29 | 4 | 10 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 36% | 11% | 50% | -3.2–2.5°C |
| February | <1% | 32% | 10% | 41% | -1.0–4.3°C |
| March | 2% | 30% | 11% | 40% | 3.3–9.2°C |
| April | 12% | 35% | 12% | 47% | 10.5–15.2°C |
| May | 34% | 37% | 12% | 49% | 16.9–21.6°C |
| June | 58% | 34% | 15% | 46% | 22.5–24.9°C |
| July | 66% | 33% | 12% | 43% | 24.8–27.7°C |
| August | 71% | 28% | 12% | 30% | 24.3–27.1°C |
| September | 54% | 27% | 12% | 36% | 20.5–23.6°C |
| October | 16% | 32% | 13% | 38% | 13.6–17.3°C |
| November | 2% | 30% | 11% | 37% | 5.8–11.4°C |
| December | <1% | 34% | 14% | 46% | -0.5–5.9°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