August
August · June · July
United States · 1991–2020
August leads for comfortable weather in Chester Hill: typically 26.2°C by day, 13.8°C at night, with 92 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 77 — days reach only 0.4°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 | 0.4°C | -8.6°C | 73 mm | 10.9 | 9 h 32 | 5 | Good coverage |
| February | 2°C | -8°C | 65 mm | 9.2 | 10 h 34 | 5 | Good coverage |
| March | 7.1°C | -4.1°C | 86 mm | 10 | 11 h 49 | 5 | Good coverage |
| April | 14.6°C | 2.1°C | 97 mm | 12 | 13 h 14 | 29 | Good coverage |
| May | 20.5°C | 8.1°C | 102 mm | 12.6 | 14 h 26 | 58 | Good coverage |
| June | 24.4°C | 12.4°C | 112 mm | 11.2 | 15 h 06 | 76 | Good coverage |
| July | 27°C | 14.5°C | 99 mm | 10.1 | 14 h 50 | 74 | Good coverage |
| August | 26.2°C | 13.8°C | 92 mm | 8.9 | 13 h 48 | 77 | Good coverage |
| September | 22.7°C | 9.9°C | 100 mm | 8.3 | 12 h 25 | 73 | Good coverage |
| October | 15.5°C | 4.3°C | 94 mm | 9.8 | 11 h 02 | 38 | Good coverage |
| November | 9.2°C | -0.7°C | 71 mm | 8.2 | 9 h 50 | 13 | Good coverage |
| December | 2.7°C | -5.3°C | 85 mm | 10 | 9 h 15 | 5 | Good coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 18.9°C9 Jan 2008 | -25.6°C22 Jan 2025 | 80 mm10 Jan 2024 | 182 mm2024 · driest 24 mm in 2025 | 28 |
| February | 23.3°C21 Feb 2018 | -25.0°C24 Feb 2015 | 50 mm4 Feb 2022 | 155 mm2018 · driest 20 mm in 2026 | 28 |
| March | 26.7°C23 Mar 2026 | -22.2°C1 Mar 2014 | 47 mm4 Mar 1999 | 163 mm2011 · driest 38 mm in 2006 | 28 |
| April | 30.6°C28 Apr 2009 | -10.0°C8 Apr 2018 | 61 mm3 Apr 2024 | 241 mm2011 · driest 40 mm in 2010 | 29 |
| May | 32.8°C31 May 2006 | -5.6°C9 May 2020 | 77 mm29 May 2017 | 185 mm2025 · driest 27 mm in 2015 | 29 |
| June | 33.9°C25 Jun 2025 | 0.6°C1 Jun 2020 | 49 mm28 Jun 2013 | 210 mm2002 · driest 45 mm in 2005 | 29 |
| July | 38.9°C23 Jul 2011 | 3.3°C2 Jul 2007 | 64 mm14 Jul 2014 | 227 mm2018 · driest 34 mm in 2002 | 29 |
| August | 36.1°C1 Aug 1999 | 3.3°C30 Aug 2025 | 68 mm10 Aug 2003 | 256 mm2003 · driest 23 mm in 2025 | 28 |
| September | 33.3°C11 Sep 2002 | -2.8°C20 Sep 2020 | 110 mm9 Sep 2004 | 269 mm2004 · driest 34 mm in 2005 | 28 |
| October | 29.4°C7 Oct 2007 | -6.1°C19 Oct 2008 | 82 mm1 Oct 2010 | 147 mm2017 · driest 43 mm in 2024 | 28 |
| November | 25.6°C5 Nov 2003 | -13.9°C11 Nov 2017 | 71 mm30 Nov 2005 | 133 mm2005 · driest 16 mm in 2012 | 28 |
| December | 20.6°C7 Dec 1998 | -22.2°C28 Dec 2017 | 83 mm1 Dec 2010 | 149 mm2012 · driest 32 mm in 2006 | 27 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 28 | 2 | 14 |
| February | 0 | 0 | 26 | 2 | 10 |
| March | <1 | 0 | 24 | 3 | 7 |
| April | 2 | <1 | 12 | 3 | 2 |
| May | 8 | <1 | 2 | 3 | <1 |
| June | 15 | 3 | 0 | 4 | 0 |
| July | 23 | 6 | 0 | 3 | 0 |
| August | 22 | 4 | 0 | 3 | 0 |
| September | 10 | 2 | <1 | 3 | 0 |
| October | 2 | 0 | 8 | 3 | <1 |
| November | <1 | 0 | 18 | 2 | 3 |
| December | 0 | 0 | 26 | 3 | 9 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 35% | 6% | 46% | -2.7–3.4°C |
| February | <1% | 32% | 8% | 37% | -1.2–5.7°C |
| March | 3% | 32% | 9% | 43% | 3.7–11.6°C |
| April | 14% | 40% | 11% | 56% | 12.4–16.8°C |
| May | 38% | 40% | 11% | 54% | 17.9–23.3°C |
| June | 58% | 37% | 13% | 49% | 23.0–25.9°C |
| July | 67% | 33% | 11% | 40% | 25.2–29.2°C |
| August | 68% | 31% | 9% | 39% | 24.3–27.8°C |
| September | 58% | 28% | 10% | 35% | 21.1–24.4°C |
| October | 20% | 31% | 9% | 33% | 13.9–17.8°C |
| November | 3% | 27% | 7% | 33% | 6.6–12.0°C |
| December | <1% | 32% | 9% | 42% | -0.3–6.5°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