September
September · June · August
United States · 1991–2020
September leads for comfortable weather in Marengo: typically 24.4°C by day, 10.7°C at night, with 74 mm of rain. Based on measured 1991–2020 NOAA station history.
September · June · August
July · August · June
September · May · October
The weakest month is January, scoring 5 against September’s 83 — days reach only -1.7°C, 26° 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 | -1.7°C | -11.1°C | 39 mm | 5.6 | 9 h 24 | 5 | Good coverage |
| February | 0.4°C | -9.6°C | 35 mm | 4.7 | 10 h 30 | 5 | Good coverage |
| March | 7.6°C | -3.4°C | 59 mm | 6.1 | 11 h 48 | 7 | Good coverage |
| April | 14.8°C | 2.2°C | 95 mm | 9.1 | 13 h 18 | 33 | Good coverage |
| May | 21.4°C | 8.3°C | 113 mm | 10.1 | 14 h 33 | 62 | Good coverage |
| June | 26.9°C | 14.2°C | 125 mm | 9 | 15 h 15 | 71 | Good coverage |
| July | 28.7°C | 16.3°C | 107 mm | 7.8 | 14 h 59 | 68 | Good coverage |
| August | 27.9°C | 15.4°C | 116 mm | 8 | 13 h 53 | 71 | Good coverage |
| September | 24.4°C | 10.7°C | 74 mm | 6 | 12 h 26 | 83 | Strong coverage |
| October | 17.2°C | 4.1°C | 74 mm | 6.9 | 10 h 59 | 49 | Strong coverage |
| November | 8.7°C | -1.9°C | 58 mm | 5.9 | 9 h 44 | 13 | Strong coverage |
| December | 1.2°C | -7.4°C | 45 mm | 5.8 | 9 h 06 | 5 | Good coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 16.7°C24 Jan 1967 | -33.9°C11 Jan 1979 | 75 mm24 Jan 1938 | 114 mm1965 · driest 3 mm in 1981 | 121 |
| February | 22.8°C25 Feb 1932 | -32.8°C13 Feb 1905 | 36 mm2 Feb 2011 | 78 mm1900 · driest 0 mm in 1969 | 119 |
| March | 28.9°C30 Mar 1986 | -26.7°C8 Mar 1943 | 53 mm19 Mar 1948 | 161 mm1976 · driest 5 mm in 2018 | 117 |
| April | 34.4°C30 Apr 1926 | -14.4°C7 Apr 1982 | 100 mm18 Apr 2013 | 200 mm1993 · driest 2 mm in 2018 | 119 |
| May | 41.7°C31 May 1934 | -6.1°C6 May 2014 | 85 mm13 May 2010 | 251 mm1996 · driest 11 mm in 1934 | 117 |
| June | 41.7°C1 Jun 1934 | -1.7°C11 Jun 1972 | 131 mm13 Jun 1999 | 264 mm1993 · driest 5 mm in 1922 | 119 |
| July | 42.8°C14 Jul 1936 | 3.9°C5 Jul 1972 | 103 mm2 Jul 1978 | 232 mm2017 · driest 8 mm in 1894 | 122 |
| August | 41.7°C5 Aug 1918 | 2.8°C30 Aug 1915 | 208 mm22 Aug 2002 | 361 mm2007 · driest 11 mm in 1893 | 122 |
| September | 39.4°C8 Sep 1922 | -4.4°C30 Sep 1899 | 229 mm7 Sep 1894 | 398 mm1894 · driest 0 mm in 2017 | 123 |
| October | 32.2°C6 Oct 1963 | -13.3°C29 Oct 1925 | 81 mm10 Oct 1954 | 194 mm1941 · driest 0 mm in 1952 | 123 |
| November | 26.7°C1 Nov 1933 | -27.2°C30 Nov 1947 | 73 mm3 Nov 1935 | 159 mm1985 · driest 3 mm in 1999 | 121 |
| December | 19.4°C4 Dec 2012 | -32.2°C27 Dec 1950 | 59 mm5 Dec 1909 | 147 mm2015 · driest 0 mm in 2014 | 118 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 27 | 1 | 5 |
| February | 0 | 0 | 25 | <1 | 3 |
| March | <1 | 0 | 22 | 2 | 1 |
| April | 2 | 0 | 10 | 3 | <1 |
| May | 9 | 3 | 1 | 4 | 0 |
| June | 21 | 9 | 0 | 4 | 0 |
| July | 26 | 11 | 0 | 3 | 0 |
| August | 25 | 9 | 0 | 3 | 0 |
| September | 15 | 4 | <1 | 2 | 0 |
| October | 4 | <1 | 7 | 3 | 0 |
| November | 0 | 0 | 19 | 2 | <1 |
| December | 0 | 0 | 27 | 1 | 3 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 18% | 4% | 13% | -6.0–1.7°C |
| February | <1% | 19% | 3% | 16% | -4.1–3.5°C |
| March | 3% | 23% | 7% | 26% | 2.9–10.1°C |
| April | 18% | 28% | 10% | 33% | 11.7–17.7°C |
| May | 45% | 29% | 10% | 35% | 18.5–24.3°C |
| June | 67% | 28% | 12% | 32% | 24.3–29.1°C |
| July | 76% | 24% | 10% | 25% | 27.6–31.2°C |
| August | 75% | 24% | 10% | 24% | 26.1–30.1°C |
| September | 61% | 24% | 10% | 23% | 21.9–26.6°C |
| October | 29% | 21% | 8% | 21% | 14.4–20.2°C |
| November | 3% | 22% | 7% | 19% | 4.9–10.7°C |
| December | 0% | 20% | 5% | 16% | -3.2–3.8°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