April
April · October · March
United States · 1991–2020
April leads for comfortable weather in Harper: typically 25.6°C by day, 11.6°C at night, with 58 mm of rain. Based on measured 1991–2020 NOAA station history.
April · October · March
July · August · June
November · March · February
The weakest month is January, scoring 46 against April’s 84 — days reach only 16°C, 8° below the 24°C the score treats as ideal, and nights drop to 1.3°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 | 16°C | 1.3°C | 42 mm | 4.9 | 10 h 23 | 46 | Strong coverage |
| February | 18.2°C | 3.7°C | 41 mm | 4.6 | 11 h 04 | 58 | Strong coverage |
| March | 21.7°C | 7.8°C | 60 mm | 5.7 | 11 h 54 | 74 | Strong coverage |
| April | 25.6°C | 11.6°C | 58 mm | 4.6 | 12 h 52 | 84 | Strong coverage |
| May | 28.8°C | 16.7°C | 109 mm | 7 | 13 h 40 | 67 | Strong coverage |
| June | 32.4°C | 20.2°C | 84 mm | 5.3 | 14 h 05 | 54 | Strong coverage |
| July | 34°C | 21.3°C | 53 mm | 3.9 | 13 h 55 | 52 | Strong coverage |
| August | 34.7°C | 21°C | 49 mm | 4.2 | 13 h 14 | 51 | Strong coverage |
| September | 31.2°C | 17.7°C | 95 mm | 6.1 | 12 h 19 | 60 | Strong coverage |
| October | 26.6°C | 12.3°C | 75 mm | 5.3 | 11 h 23 | 79 | Strong coverage |
| November | 20.5°C | 6.8°C | 56 mm | 5 | 10 h 35 | 69 | Strong coverage |
| December | 16.7°C | 2.3°C | 47 mm | 4.7 | 10 h 12 | 50 | 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 | 30.6°C27 Jan 1975 | -14.4°C11 Jan 1982 | 75 mm24 Jan 2026 | 130 mm1989 · driest 0 mm in 1996 | 52 |
| February | 36.1°C22 Feb 1996 | -17.2°C2 Feb 1985 | 81 mm14 Feb 2017 | 162 mm1992 · driest 1 mm in 1999 | 52 |
| March | 35.0°C6 Mar 1991 | -11.7°C4 Mar 2002 | 84 mm12 Mar 2009 | 245 mm2007 · driest 2 mm in 2011 | 52 |
| April | 37.8°C18 Apr 2006 | -5.6°C3 Apr 1987 | 93 mm6 Apr 2004 | 205 mm2004 · driest 2 mm in 2012 | 52 |
| May | 40.6°C28 May 2024 | 0.6°C4 May 2013 | 116 mm29 May 2016 | 346 mm2016 · driest 17 mm in 2003 | 52 |
| June | 41.7°C22 Jun 2023 | 8.9°C12 Jun 1979 | 153 mm22 Jun 1997 | 309 mm2004 · driest 0 mm in 1990 | 52 |
| July | 40.6°C24 Jul 2018 | 12.2°C31 Jul 1984 | 213 mm16 Jul 2026 | 484 mm2002 · driest 0 mm in 1993 | 52 |
| August | 42.2°C29 Aug 2011 | 12.2°C28 Aug 1992 | 295 mm2 Aug 1978 | 443 mm1978 · driest 0 mm in 1993 | 50 |
| September | 42.8°C6 Sep 2000 | 2.8°C22 Sep 1983 | 123 mm15 Sep 1991 | 240 mm1980 · driest 10 mm in 1997 | 51 |
| October | 36.1°C12 Oct 2020 | -6.1°C31 Oct 1993 | 146 mm31 Oct 1974 | 246 mm2018 · driest 1 mm in 2024 | 52 |
| November | 33.3°C8 Nov 2025 | -11.1°C29 Nov 1976 | 74 mm19 Nov 1992 | 217 mm2000 · driest 0 mm in 1999 | 51 |
| December | 31.1°C31 Dec 2024 | -17.8°C23 Dec 1989 | 106 mm20 Dec 1991 | 309 mm1991 · driest 0 mm in 2005 | 51 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) |
|---|---|---|---|---|
| January | 2 | 0 | 15 | 2 |
| February | 4 | <1 | 9 | 1 |
| March | 10 | 2 | 3 | 2 |
| April | 19 | 5 | <1 | 2 |
| May | 27 | 13 | 0 | 4 |
| June | 30 | 25 | 0 | 2 |
| July | 31 | 29 | 0 | 2 |
| August | 31 | 29 | 0 | 2 |
| September | 28 | 21 | 0 | 3 |
| October | 22 | 8 | <1 | 2 |
| November | 7 | <1 | 5 | 2 |
| December | 2 | 0 | 13 | 1 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 27% | 16% | 4% | 14% | 12.2–18.6°C |
| February | 39% | 16% | 5% | 14% | 14.3–22.0°C |
| March | 60% | 17% | 6% | 14% | 19.2–23.7°C |
| April | 77% | 16% | 7% | 13% | 23.6–27.0°C |
| May | 76% | 23% | 11% | 23% | 26.3–31.2°C |
| June | 82% | 18% | 8% | 18% | 30.0–34.7°C |
| July | 86% | 14% | 6% | 13% | 31.3–36.7°C |
| August | 87% | 13% | 4% | 10% | 32.0–36.4°C |
| September | 80% | 19% | 8% | 17% | 28.8–33.5°C |
| October | 78% | 18% | 7% | 18% | 24.5–28.4°C |
| November | 54% | 17% | 5% | 15% | 17.6–23.5°C |
| December | 30% | 16% | 4% | 15% | 14.0–18.5°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