September
September · May · October
United States · 1991–2020
September leads for comfortable weather in Aetna: typically 27.6°C by day, 15.4°C at night, with 96 mm of rain. Based on measured 1991–2020 NOAA station history.
September · May · October
August · June · July
October · April · November
The weakest month is January, scoring 5 against September’s 76 — days reach only 8.5°C, 15° below the 24°C the score treats as ideal, and nights drop to -2.4°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 | 8.5°C | -2.4°C | 117 mm | 8.8 | 9 h 59 | 5 | Good coverage |
| February | 10.7°C | -0.7°C | 141 mm | 9.3 | 10 h 50 | 7 | Good coverage |
| March | 16.2°C | 4°C | 128 mm | 10.2 | 11 h 51 | 35 | Good coverage |
| April | 21.5°C | 8.5°C | 140 mm | 9.1 | 13 h 02 | 60 | Good coverage |
| May | 25°C | 13.4°C | 140 mm | 10.2 | 14 h 02 | 72 | Good coverage |
| June | 29°C | 17.9°C | 114 mm | 8.6 | 14 h 33 | 62 | Good coverage |
| July | 30.4°C | 19.7°C | 127 mm | 8.6 | 14 h 21 | 53 | Good coverage |
| August | 30.6°C | 19.1°C | 99 mm | 7.7 | 13 h 30 | 58 | Good coverage |
| September | 27.6°C | 15.4°C | 96 mm | 6.3 | 12 h 22 | 76 | Good coverage |
| October | 21.9°C | 9.1°C | 110 mm | 6.9 | 11 h 13 | 69 | Good coverage |
| November | 15.8°C | 3.7°C | 103 mm | 7.8 | 10 h 14 | 39 | Good coverage |
| December | 10°C | -0.5°C | 133 mm | 9.3 | 9 h 45 | 7 | Good coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 26.1°C13 Jan 1911 | -24.4°C22 Jan 1918 | 125 mm1 Jan 1919 | 304 mm1913 · driest 35 mm in 2003 | 56 |
| February | 26.7°C17 Feb 1927 | -30.6°C14 Feb 1905 | 89 mm14 Feb 2003 | 343 mm2018 · driest 30 mm in 1906 | 59 |
| March | 31.7°C25 Mar 1929 | -17.2°C7 Mar 1899 | 136 mm28 Mar 1902 | 417 mm1897 · driest 28 mm in 1918 | 58 |
| April | 36.7°C27 Apr 1914 | -7.8°C17 Apr 1905 | 162 mm1 Apr 1920 | 442 mm1920 · driest 24 mm in 1915 | 59 |
| May | 36.1°C25 May 1904 | -2.8°C8 May 1906 | 145 mm2 May 2010 | 361 mm2010 · driest 14 mm in 2005 | 58 |
| June | 40.0°C25 Jun 1914 | 1.7°C13 Jun 1903 | 174 mm5 Jun 2014 | 456 mm1900 · driest 12 mm in 1930 | 58 |
| July | 42.2°C29 Jul 1930 | 5.6°C8 Jul 1906 | 159 mm28 Jul 2017 | 314 mm2017 · driest 27 mm in 1930 | 59 |
| August | 41.1°C9 Aug 1930 | 6.1°C17 Aug 1897 | 125 mm19 Aug 2010 | 295 mm1923 · driest 14 mm in 1909 | 59 |
| September | 41.7°C7 Sep 1925 | -2.2°C27 Sep 1899 | 149 mm13 Sep 2020 | 215 mm2020 · driest 0 mm in 2019 | 60 |
| October | 35.0°C1 Oct 1919 | -8.9°C25 Oct 1903 | 97 mm19 Oct 2004 | 244 mm2019 · driest 1 mm in 2000 | 61 |
| November | 30.6°C3 Nov 2000 | -16.7°C21 Nov 2000 | 119 mm21 Nov 1900 | 264 mm1919 · driest 28 mm in 1924 | 60 |
| December | 24.4°C13 Dec 1927 | -24.4°C23 Dec 2022 | 103 mm27 Dec 1904 | 386 mm1911 · driest 16 mm in 2006 | 60 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 20 | 4 | <1 |
| February | <1 | 0 | 16 | 4 | <1 |
| March | 3 | 0 | 9 | 4 | <1 |
| April | 9 | <1 | 1 | 4 | 0 |
| May | 18 | 2 | 0 | 4 | 0 |
| June | 28 | 13 | 0 | 4 | 0 |
| July | 29 | 19 | 0 | 4 | 0 |
| August | 29 | 18 | 0 | 3 | 0 |
| September | 23 | 9 | 0 | 2 | 0 |
| October | 11 | 1 | 1 | 3 | 0 |
| November | 1 | 0 | 8 | 3 | <1 |
| December | 0 | 0 | 17 | 4 | <1 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 3% | 30% | 15% | 35% | 5.4–13.4°C |
| February | 8% | 32% | 16% | 39% | 7.5–15.0°C |
| March | 26% | 32% | 16% | 38% | 13.2–21.0°C |
| April | 47% | 31% | 15% | 35% | 19.6–23.9°C |
| May | 62% | 31% | 14% | 38% | 23.9–28.1°C |
| June | 71% | 29% | 13% | 30% | 27.7–32.3°C |
| July | 70% | 30% | 13% | 32% | 29.6–33.1°C |
| August | 74% | 25% | 11% | 27% | 29.4–33.1°C |
| September | 77% | 19% | 8% | 16% | 26.0–30.9°C |
| October | 60% | 19% | 9% | 18% | 20.9–24.8°C |
| November | 23% | 24% | 11% | 22% | 13.8–18.8°C |
| December | 4% | 28% | 14% | 31% | 7.5–14.3°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