September
September · August · June
United States · 1991–2020
September leads for comfortable weather in Arnolds Park: typically 23.3°C by day, 10.8°C at night, with 81 mm of rain. Based on measured 1991–2020 NOAA station history.
September · August · June
July · August · June
September · May · October
The weakest month is January, scoring 5 against September’s 81 — days reach only -4.2°C, 28° below the 24°C the score treats as ideal.
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 | -4.2°C | -13.7°C | 21 mm | 4.2 | 9 h 18 | 5 | Strong coverage |
| February | -1.7°C | -11.4°C | 20 mm | 4.2 | 10 h 26 | 5 | Strong coverage |
| March | 5.5°C | -4.8°C | 39 mm | 4.8 | 11 h 47 | 5 | Strong coverage |
| April | 14°C | 1.7°C | 82 mm | 7.3 | 13 h 21 | 33 | Strong coverage |
| May | 20.8°C | 8.7°C | 103 mm | 9.4 | 14 h 40 | 63 | Strong coverage |
| June | 26.2°C | 14.6°C | 122 mm | 8.3 | 15 h 23 | 75 | Strong coverage |
| July | 28.1°C | 16.8°C | 87 mm | 7.2 | 15 h 06 | 72 | Strong coverage |
| August | 26.7°C | 15.4°C | 88 mm | 6.3 | 13 h 58 | 80 | Strong coverage |
| September | 23.3°C | 10.8°C | 81 mm | 6 | 12 h 27 | 81 | Strong coverage |
| October | 15.6°C | 3.5°C | 56 mm | 5.4 | 10 h 57 | 46 | Strong coverage |
| November | 6.2°C | -4.3°C | 37 mm | 4.5 | 9 h 38 | 5 | Strong coverage |
| December | -1.7°C | -10.6°C | 23 mm | 4.3 | 8 h 59 | 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 | 17.2°C24 Jan 1981 | -36.7°C3 Jan 2010 | 30 mm31 Jan 2010 | 60 mm2010 · driest 0 mm in 2025 | 91 |
| February | 18.3°C26 Feb 2024 | -33.3°C2 Feb 1996 | 45 mm28 Feb 1951 | 73 mm1971 · driest 0 mm in 2008 | 92 |
| March | 29.4°C31 Mar 2026 | -30.0°C5 Mar 1960 | 66 mm23 Mar 1987 | 113 mm1987 · driest 3 mm in 1994 | 91 |
| April | 33.9°C30 Apr 2007 | -16.7°C1 Apr 1924 | 67 mm22 Apr 1985 | 177 mm1991 · driest 6 mm in 1959 | 91 |
| May | 36.7°C14 May 2013 | -7.8°C3 May 1967 | 78 mm5 May 2007 | 262 mm1959 · driest 8 mm in 1925 | 91 |
| June | 38.9°C8 Jun 1985 | 1.1°C4 Jun 1945 | 158 mm24 Jun 2018 | 381 mm2018 · driest 5 mm in 2019 | 91 |
| July | 39.4°C31 Jul 1955 | 4.4°C22 Jul 1925 | 157 mm4 Jul 1962 | 268 mm1987 · driest 3 mm in 1959 | 90 |
| August | 38.9°C13 Aug 1965 | 1.7°C20 Aug 1950 | 128 mm30 Aug 1962 | 278 mm2017 · driest 10 mm in 1976 | 86 |
| September | 37.8°C6 Sep 1976 | -4.4°C23 Sep 1983 | 151 mm15 Sep 2004 | 330 mm2004 · driest 5 mm in 2024 | 87 |
| October | 33.3°C5 Oct 1963 | -23.3°C29 Oct 1925 | 78 mm1 Oct 2021 | 154 mm2021 · driest 0 mm in 1989 | 89 |
| November | 25.6°C8 Nov 1999 | -25.6°C27 Nov 2014 | 76 mm9 Nov 1977 | 137 mm2015 · driest 1 mm in 2023 | 90 |
| December | 19.4°C5 Dec 1939 | -33.9°C28 Dec 1924 | 31 mm27 Dec 2018 | 76 mm1982 · driest 1 mm in 2002 | 90 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 31 | <1 | 5 |
| February | 0 | 0 | 27 | <1 | 5 |
| March | <1 | 0 | 25 | 1 | 2 |
| April | 2 | <1 | 11 | 3 | <1 |
| May | 8 | 2 | 1 | 3 | 0 |
| June | 19 | 6 | 0 | 4 | 0 |
| July | 26 | 10 | 0 | 3 | 0 |
| August | 22 | 6 | 0 | 3 | 0 |
| September | 13 | 3 | <1 | 2 | 0 |
| October | 3 | <1 | 9 | 2 | <1 |
| November | <1 | 0 | 23 | 1 | 2 |
| December | 0 | 0 | 30 | <1 | 4 |
The best month has moved. On the 1961–1990 numbers the strongest month here was August (scoring 80); on 2011–2025 it is September (88). 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 | 0% | 12% | <1% | 5% | -8.4–-0.3°C |
| February | 0% | 13% | 2% | 8% | -5.6–3.0°C |
| March | 4% | 18% | 4% | 15% | 0.8–10.1°C |
| April | 20% | 25% | 9% | 27% | 10.3–17.9°C |
| May | 47% | 30% | 10% | 35% | 18.6–24.2°C |
| June | 67% | 29% | 12% | 34% | 24.4–28.5°C |
| July | 76% | 23% | 9% | 21% | 26.5–30.9°C |
| August | 77% | 22% | 9% | 20% | 25.0–29.1°C |
| September | 61% | 21% | 8% | 21% | 20.5–25.4°C |
| October | 28% | 17% | 5% | 14% | 13.1–19.2°C |
| November | 2% | 15% | 4% | 11% | 1.9–9.5°C |
| December | 0% | 12% | 2% | 6% | -5.9–2.3°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