September
September · August · June
United States · 1991–2020
September leads for comfortable weather in Backbone: typically 24.8°C by day, 11.1°C at night, with 90 mm of rain. Based on measured 1991–2020 NOAA station history.
September · August · June
August · July · June
October · September · April
The weakest month is January, scoring 5 against September’s 79 — days reach only 4.8°C, 19° below the 24°C the score treats as ideal, and nights drop to -6.2°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 | 4.8°C | -6.2°C | 76 mm | 8.5 | 9 h 49 | 5 | Strong coverage |
| February | 7°C | -5.1°C | 72 mm | 8.2 | 10 h 44 | 5 | Strong coverage |
| March | 11.9°C | -2°C | 92 mm | 9.5 | 11 h 50 | 15 | Strong coverage |
| April | 18.5°C | 2.7°C | 93 mm | 10 | 13 h 07 | 45 | Strong coverage |
| May | 22.6°C | 8.2°C | 116 mm | 11.8 | 14 h 11 | 64 | Strong coverage |
| June | 26.2°C | 12.9°C | 104 mm | 10.4 | 14 h 46 | 73 | Strong coverage |
| July | 28.1°C | 15.4°C | 104 mm | 10.2 | 14 h 32 | 70 | Strong coverage |
| August | 27.7°C | 14.8°C | 84 mm | 9.4 | 13 h 37 | 75 | Strong coverage |
| September | 24.8°C | 11.1°C | 90 mm | 7.6 | 12 h 23 | 79 | Strong coverage |
| October | 19°C | 4.1°C | 69 mm | 7.1 | 11 h 09 | 55 | Strong coverage |
| November | 12.6°C | -1.6°C | 65 mm | 6.8 | 10 h 05 | 25 | Strong coverage |
| December | 6.9°C | -4.2°C | 85 mm | 9.2 | 9 h 34 | 5 | 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 | 25.0°C26 Jan 1950 | -28.3°C21 Jan 1918 | 69 mm20 Jan 1898 | 245 mm1898 · driest 0 mm in 1896 | 111 |
| February | 26.1°C26 Feb 1977 | -26.7°C6 Feb 1996 | 53 mm24 Feb 1984 | 225 mm2025 · driest 0 mm in 1896 | 112 |
| March | 31.1°C25 Mar 1929 | -22.2°C8 Mar 1960 | 84 mm12 Mar 1963 | 210 mm1935 · driest 0 mm in 1896 | 112 |
| April | 35.6°C25 Apr 1925 | -11.1°C8 Apr 1896 | 86 mm5 Apr 1977 | 180 mm1987 · driest 15 mm in 1942 | 112 |
| May | 35.6°C22 May 1941 | -6.1°C1 May 1927 | 60 mm6 May 2018 | 197 mm2003 · driest 28 mm in 1964 | 112 |
| June | 37.2°C10 Jun 1974 | -1.1°C2 Jun 1966 | 211 mm24 Jun 2016 | 329 mm2016 · driest 8 mm in 1898 | 113 |
| July | 38.9°C14 Jul 1954 | 2.2°C10 Jul 1961 | 89 mm19 Jul 1954 | 241 mm1938 · driest 15 mm in 2011 | 113 |
| August | 37.8°C21 Aug 1983 | 2.2°C29 Aug 1986 | 77 mm20 Aug 1969 | 291 mm1984 · driest 14 mm in 1976 | 112 |
| September | 39.4°C9 Sep 1985 | -3.3°C28 Sep 1942 | 84 mm29 Sep 1967 | 261 mm2004 · driest 5 mm in 1985 | 113 |
| October | 33.9°C4 Oct 2019 | -12.8°C27 Oct 1962 | 93 mm16 Oct 1954 | 186 mm2017 · driest 0 mm in 2000 | 112 |
| November | 27.8°C2 Nov 1927 | -18.3°C30 Nov 1929 | 90 mm5 Nov 1985 | 208 mm1985 · driest 3 mm in 2001 | 110 |
| December | 25.0°C7 Dec 1951 | -36.7°C30 Dec 1917 | 58 mm9 Dec 2009 | 180 mm2009 · driest 7 mm in 1965 | 110 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 26 | 3 | 3 |
| February | 0 | 0 | 24 | 2 | 3 |
| March | <1 | 0 | 21 | 3 | 2 |
| April | 5 | <1 | 11 | 3 | <1 |
| May | 13 | 1 | 2 | 4 | 0 |
| June | 21 | 4 | 0 | 3 | 0 |
| July | 27 | 10 | 0 | 4 | 0 |
| August | 26 | 8 | 0 | 3 | 0 |
| September | 16 | 3 | <1 | 3 | 0 |
| October | 4 | <1 | 8 | 2 | <1 |
| November | <1 | 0 | 21 | 3 | <1 |
| December | 0 | 0 | 25 | 3 | 2 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 1% | 29% | 9% | 33% | 2.3–9.0°C |
| February | 2% | 30% | 10% | 37% | 4.3–11.6°C |
| March | 14% | 31% | 11% | 39% | 8.8–16.7°C |
| April | 38% | 32% | 10% | 41% | 16.6–22.4°C |
| May | 55% | 36% | 12% | 47% | 20.9–26.8°C |
| June | 66% | 32% | 11% | 40% | 25.6–29.3°C |
| July | 66% | 33% | 12% | 42% | 27.4–31.1°C |
| August | 70% | 29% | 10% | 32% | 26.5–30.2°C |
| September | 70% | 24% | 9% | 24% | 23.1–27.8°C |
| October | 48% | 21% | 8% | 21% | 17.6–22.5°C |
| November | 12% | 25% | 8% | 26% | 9.8–16.0°C |
| December | 2% | 28% | 9% | 32% | 4.0–10.2°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