September
September · May · October
United States · 1991–2020
September leads for comfortable weather in Hatfield: typically 28.5°C by day, 15.5°C at night, with 122 mm of rain. Based on measured 1991–2020 NOAA station history.
September · May · October
June · August · July
October · April · March
The weakest month is January, scoring 9 against September’s 69 — days reach only 9.7°C, 14° below the 24°C the score treats as ideal, and nights drop to -2°C.
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 | 9.7°C | -2°C | 101 mm | 7.6 | 10 h 05 | 9 | Strong coverage |
| February | 12.3°C | -0.3°C | 104 mm | 8.2 | 10 h 53 | 19 | Strong coverage |
| March | 16.7°C | 3.9°C | 139 mm | 9.3 | 11 h 52 | 35 | Strong coverage |
| April | 21.4°C | 8.2°C | 157 mm | 8.6 | 13 h 00 | 57 | Strong coverage |
| May | 25.2°C | 13.8°C | 184 mm | 9.5 | 13 h 57 | 67 | Strong coverage |
| June | 29.5°C | 18.3°C | 117 mm | 8.1 | 14 h 27 | 60 | Strong coverage |
| July | 32.1°C | 20.2°C | 128 mm | 8.3 | 14 h 15 | 46 | Strong coverage |
| August | 32.1°C | 19.4°C | 101 mm | 6.8 | 13 h 27 | 53 | Strong coverage |
| September | 28.5°C | 15.5°C | 122 mm | 6.7 | 12 h 21 | 69 | Strong coverage |
| October | 22.6°C | 9.3°C | 134 mm | 7.5 | 11 h 15 | 67 | Strong coverage |
| November | 16.1°C | 3.6°C | 138 mm | 7.4 | 10 h 19 | 35 | Strong coverage |
| December | 10.9°C | -0.6°C | 134 mm | 8.1 | 9 h 51 | 10 | 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 | 27.8°C23 Jan 1943 | -23.3°C18 Jan 1930 | 194 mm24 Jan 1949 | 367 mm1949 · driest 6 mm in 1943 | 132 |
| February | 28.9°C22 Feb 1996 | -26.1°C12 Feb 1899 | 122 mm21 Feb 2018 | 322 mm2018 · driest 12 mm in 1947 | 133 |
| March | 32.2°C31 Mar 1974 | -14.4°C3 Mar 1943 | 155 mm19 Mar 2008 | 458 mm1945 · driest 27 mm in 1925 | 134 |
| April | 33.3°C19 Apr 1987 | -6.1°C24 Apr 1903 | 124 mm21 Apr 1927 | 396 mm1927 · driest 9 mm in 1987 | 135 |
| May | 37.2°C31 May 1934 | -0.6°C1 May 1903 | 180 mm31 May 2013 | 545 mm2015 · driest 26 mm in 1970 | 135 |
| June | 40.6°C22 Jun 1936 | 6.7°C1 Jun 1983 | 163 mm26 Jun 1999 | 354 mm1999 · driest 4 mm in 1954 | 135 |
| July | 43.3°C8 Jul 1897 | 8.9°C24 Jul 1904 | 171 mm28 Jul 1991 | 377 mm1953 · driest 5 mm in 1976 | 136 |
| August | 44.4°C10 Aug 1936 | 8.3°C24 Aug 1891 | 192 mm13 Aug 2020 | 490 mm2020 · driest 0 mm in 1923 | 134 |
| September | 41.7°C8 Sep 1925 | 1.1°C29 Sep 1967 | 130 mm30 Sep 1954 | 353 mm1923 · driest 1 mm in 2004 | 133 |
| October | 37.8°C1 Oct 1938 | -6.7°C31 Oct 1993 | 302 mm8 Oct 1990 | 424 mm1984 · driest 1 mm in 2005 | 132 |
| November | 29.4°C5 Nov 1891 | -10.6°C15 Nov 1940 | 141 mm28 Nov 2015 | 405 mm2015 · driest 2 mm in 1903 | 133 |
| December | 26.7°C7 Dec 1939 | -21.7°C24 Dec 1989 | 175 mm10 Dec 1971 | 362 mm1971 · driest 1 mm in 1950 | 131 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 22 | 3 | <1 |
| February | <1 | 0 | 17 | 3 | <1 |
| March | 2 | 0 | 9 | 4 | <1 |
| April | 8 | <1 | 2 | 5 | 0 |
| May | 19 | 3 | 0 | 5 | 0 |
| June | 28 | 15 | 0 | 4 | 0 |
| July | 30 | 24 | 0 | 3 | 0 |
| August | 30 | 23 | 0 | 3 | 0 |
| September | 24 | 12 | 0 | 4 | 0 |
| October | 12 | 2 | 1 | 4 | 0 |
| November | 1 | 0 | 10 | 4 | 0 |
| December | 0 | 0 | 19 | 4 | <1 |
The best month has moved. On the 1961–1990 numbers the strongest month here was May (scoring 74); on 2011–2025 it is October (79). 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 | 5% | 24% | 10% | 24% | 7.3–13.1°C |
| February | 12% | 26% | 11% | 28% | 9.4–15.7°C |
| March | 30% | 27% | 14% | 28% | 14.0–20.6°C |
| April | 54% | 29% | 15% | 34% | 20.2–24.3°C |
| May | 65% | 32% | 16% | 38% | 23.8–28.0°C |
| June | 73% | 27% | 12% | 29% | 28.3–32.5°C |
| July | 75% | 25% | 12% | 25% | 30.5–34.8°C |
| August | 79% | 21% | 10% | 21% | 30.0–35.8°C |
| September | 77% | 22% | 10% | 21% | 26.7–31.5°C |
| October | 65% | 21% | 10% | 22% | 21.2–25.9°C |
| November | 27% | 22% | 11% | 22% | 13.8–18.8°C |
| December | 6% | 24% | 11% | 26% | 8.8–14.0°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