May
May · September · June
United States · 1991–2020
May leads for comfortable weather in Upper Roxborough: typically 23.9°C by day, 11.3°C at night, with 116 mm of rain. Based on measured 1991–2020 NOAA station history.
May · September · June
July · August · June
October · April · May
The weakest month is January, scoring 5 against May’s 75 — days reach only 5.4°C, 19° 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 | 5.4°C | -5°C | 88 mm | 8.8 | 9 h 37 | 5 | Good coverage |
| February | 6.5°C | -4.1°C | 80 mm | 7.7 | 10 h 37 | 5 | Good coverage |
| March | 11.3°C | -0.1°C | 103 mm | 8.7 | 11 h 49 | 16 | Good coverage |
| April | 18.2°C | 5.5°C | 103 mm | 10 | 13 h 12 | 48 | Good coverage |
| May | 23.9°C | 11.3°C | 116 mm | 10.7 | 14 h 22 | 75 | Good coverage |
| June | 28.8°C | 16.6°C | 133 mm | 9.7 | 15 h 00 | 62 | Good coverage |
| July | 31.6°C | 19.6°C | 122 mm | 8.8 | 14 h 45 | 49 | Good coverage |
| August | 30.5°C | 18.7°C | 139 mm | 8.5 | 13 h 45 | 52 | Good coverage |
| September | 27°C | 14.5°C | 118 mm | 7.5 | 12 h 24 | 74 | Good coverage |
| October | 20.4°C | 7.8°C | 123 mm | 8.7 | 11 h 04 | 58 | Good coverage |
| November | 13.8°C | 1.8°C | 93 mm | 7.9 | 9 h 54 | 30 | Good coverage |
| December | 8°C | -2.1°C | 127 mm | 9 | 9 h 20 | 5 | Good 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°C7 Jan 2007 | -24.4°C18 Jan 1982 | 91 mm10 Jan 2024 | 236 mm1979 · driest 13 mm in 1981 | 58 |
| February | 25.6°C22 Feb 2018 | -20.6°C19 Feb 1979 | 51 mm17 Feb 2003 | 168 mm2014 · driest 8 mm in 2002 | 61 |
| March | 30.0°C30 Mar 2025 | -13.3°C1 Mar 1980 | 66 mm24 Mar 2024 | 209 mm2010 · driest 29 mm in 2006 | 59 |
| April | 36.7°C19 Apr 1976 | -9.4°C7 Apr 1982 | 107 mm16 Apr 2007 | 278 mm2007 · driest 13 mm in 1963 | 61 |
| May | 36.7°C19 May 1962 | -1.7°C10 May 1966 | 93 mm1 May 2014 | 260 mm2014 · driest 9 mm in 2015 | 61 |
| June | 37.8°C26 Jun 1952 | 5.0°C11 Jun 1972 | 92 mm17 Jun 2001 | 274 mm2013 · driest 12 mm in 1966 | 61 |
| July | 42.2°C24 Jul 2011 | 8.9°C3 Jul 2011 | 123 mm27 Jul 1986 | 275 mm2004 · driest 15 mm in 1962 | 60 |
| August | 41.1°C10 Aug 2001 | 4.4°C30 Aug 1982 | 164 mm28 Aug 2011 | 460 mm2011 · driest 11 mm in 1964 | 62 |
| September | 38.9°C2 Sep 1953 | 1.1°C18 Sep 2014 | 154 mm29 Sep 2004 | 267 mm2011 · driest 13 mm in 2007 | 58 |
| October | 33.3°C3 Oct 2019 | -3.3°C26 Oct 1952 | 178 mm1 Oct 2010 | 262 mm2007 · driest 0 mm in 2024 | 59 |
| November | 29.4°C2 Nov 1971 | -10.0°C15 Nov 1986 | 77 mm9 Nov 1972 | 227 mm1972 · driest 13 mm in 1976 | 57 |
| December | 24.4°C6 Dec 2001 | -23.3°C25 Dec 1983 | 78 mm18 Dec 2023 | 229 mm2009 · driest 7 mm in 1955 | 60 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 25 | 3 | 3 |
| February | <1 | 0 | 23 | 3 | 3 |
| March | <1 | 0 | 16 | 4 | 2 |
| April | 4 | 1 | 3 | 3 | <1 |
| May | 13 | 6 | 0 | 4 | 0 |
| June | 25 | 14 | 0 | 4 | 0 |
| July | 30 | 23 | 0 | 4 | 0 |
| August | 29 | 20 | 0 | 4 | 0 |
| September | 21 | 8 | 0 | 3 | 0 |
| October | 7 | <1 | 1 | 4 | <1 |
| November | <1 | 0 | 12 | 3 | <1 |
| December | 0 | 0 | 22 | 4 | 2 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | <1% | 26% | 9% | 28% | 1.4–7.5°C |
| February | 1% | 27% | 9% | 29% | 2.1–9.0°C |
| March | 7% | 28% | 11% | 34% | 8.0–13.4°C |
| April | 27% | 31% | 11% | 37% | 15.4–20.0°C |
| May | 56% | 31% | 12% | 42% | 21.0–25.4°C |
| June | 70% | 29% | 11% | 33% | 26.5–29.8°C |
| July | 74% | 27% | 12% | 30% | 29.1–32.5°C |
| August | 74% | 26% | 11% | 29% | 27.8–32.1°C |
| September | 72% | 23% | 10% | 21% | 24.2–28.4°C |
| October | 41% | 23% | 10% | 23% | 18.1–21.7°C |
| November | 9% | 26% | 10% | 29% | 11.1–16.0°C |
| December | 2% | 27% | 12% | 30% | 3.7–10.0°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