September
September · October · May
United States · 1991–2020
September leads for comfortable weather in Oak Ridge: typically 27.4°C by day, 14.3°C at night, with 126 mm of rain. Based on measured 1991–2020 NOAA station history.
September · October · May
August · July · June
October · April · March
The weakest month is January, scoring 5 against September’s 71 — days reach only 6°C, 18° below the 24°C the score treats as ideal, and nights drop to -5.4°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 | 6°C | -5.4°C | 52 mm | 5.7 | 9 h 48 | 5 | Strong coverage |
| February | 9.1°C | -3.4°C | 59 mm | 5.8 | 10 h 44 | 12 | Strong coverage |
| March | 14.5°C | 1.5°C | 89 mm | 8.5 | 11 h 50 | 32 | Strong coverage |
| April | 20°C | 6.8°C | 134 mm | 9.3 | 13 h 07 | 53 | Strong coverage |
| May | 24.4°C | 12.2°C | 190 mm | 11.2 | 14 h 11 | 64 | Strong coverage |
| June | 29.2°C | 17.5°C | 144 mm | 9.6 | 14 h 46 | 57 | Strong coverage |
| July | 31.9°C | 20°C | 110 mm | 7.1 | 14 h 33 | 50 | Strong coverage |
| August | 31.7°C | 19°C | 95 mm | 6.5 | 13 h 37 | 56 | Strong coverage |
| September | 27.4°C | 14.3°C | 126 mm | 7.3 | 12 h 23 | 71 | Strong coverage |
| October | 21.4°C | 7.9°C | 98 mm | 8.1 | 11 h 09 | 65 | Strong coverage |
| November | 14.2°C | 1.8°C | 93 mm | 7 | 10 h 04 | 32 | Strong coverage |
| December | 8.1°C | -2.8°C | 69 mm | 6.1 | 9 h 33 | 8 | Strong coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 23.9°C22 Jan 1909 | -31.1°C13 Jan 1912 | 76 mm5 Jan 2005 | 144 mm2005 · driest 0 mm in 1991 | 56 |
| February | 28.9°C1 Feb 1911 | -29.4°C9 Feb 1979 | 99 mm21 Feb 1997 | 152 mm1911 · driest 0 mm in 2006 | 56 |
| March | 33.9°C20 Mar 1907 | -22.2°C5 Mar 2014 | 112 mm1 Mar 2015 | 218 mm2021 · driest 12 mm in 2002 | 56 |
| April | 36.7°C18 Apr 2006 | -7.2°C3 Apr 1987 | 163 mm11 Apr 1994 | 441 mm1994 · driest 5 mm in 1989 | 57 |
| May | 35.6°C24 May 1911 | -3.9°C6 May 1989 | 165 mm12 May 2010 | 495 mm2019 · driest 3 mm in 1911 | 57 |
| June | 43.3°C21 Jun 1911 | 3.9°C2 Jun 1912 | 115 mm14 Jun 2001 | 348 mm2008 · driest 15 mm in 1991 | 56 |
| July | 42.2°C3 Jul 1911 | 9.4°C25 Jul 1911 | 108 mm11 Jul 1992 | 289 mm1992 · driest 13 mm in 2012 | 54 |
| August | 43.9°C3 Aug 2011 | 6.7°C26 Aug 1910 | 102 mm4 Aug 2013 | 220 mm2019 · driest 8 mm in 2000 | 56 |
| September | 45.6°C8 Sep 1912 | -2.8°C30 Sep 1984 | 107 mm14 Sep 1993 | 378 mm1993 · driest 8 mm in 1989 | 57 |
| October | 35.0°C2 Oct 1909 | -7.8°C31 Oct 1993 | 173 mm3 Oct 1986 | 376 mm1986 · driest 3 mm in 2023 | 56 |
| November | 31.1°C7 Nov 1907 | -18.9°C8 Nov 1991 | 82 mm21 Nov 1979 | 250 mm2015 · driest 0 mm in 1989 | 57 |
| December | 25.6°C26 Dec 2025 | -27.8°C22 Dec 1989 | 132 mm27 Dec 2015 | 276 mm2015 · driest 2 mm in 2000 | 57 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 24 | 1 | <1 |
| February | <1 | 0 | 20 | 2 | <1 |
| March | 2 | <1 | 12 | 3 | <1 |
| April | 7 | <1 | 3 | 4 | 0 |
| May | 16 | 4 | <1 | 5 | 0 |
| June | 27 | 15 | 0 | 4 | 0 |
| July | 30 | 23 | 0 | 3 | 0 |
| August | 29 | 21 | 0 | 3 | 0 |
| September | 22 | 10 | <1 | 3 | 0 |
| October | 10 | 2 | 2 | 3 | 0 |
| November | 1 | 0 | 12 | 3 | 0 |
| December | 0 | 0 | 21 | 2 | <1 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 3% | 15% | 4% | 11% | 2.4–10.2°C |
| February | 8% | 19% | 7% | 16% | 3.6–12.9°C |
| March | 22% | 25% | 9% | 27% | 10.3–19.1°C |
| April | 39% | 29% | 13% | 33% | 17.3–22.6°C |
| May | 56% | 33% | 16% | 41% | 22.5–26.8°C |
| June | 69% | 30% | 15% | 36% | 27.3–30.9°C |
| July | 79% | 22% | 10% | 19% | 30.1–34.7°C |
| August | 79% | 21% | 9% | 20% | 29.2–34.8°C |
| September | 75% | 22% | 11% | 23% | 25.9–30.2°C |
| October | 51% | 22% | 10% | 24% | 19.2–23.8°C |
| November | 18% | 19% | 8% | 16% | 10.8–17.2°C |
| December | 3% | 18% | 6% | 16% | 5.2–10.8°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