September
September · June · August
United States · 1991–2020
September leads for comfortable weather in Riverview: typically 24°C by day, 13.5°C at night, with 96 mm of rain. Based on measured 1991–2020 NOAA station history.
September · June · August
July · August · June
May · October · September
The weakest month is January, scoring 5 against September’s 84 — days reach only 0.1°C, 24° 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 | Sea | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|---|
| January | 0.1°C | -7°C | 72 mm | 11.5 | 1.1°C | 9 h 25 | 5 | Good coverage |
| February | 2.2°C | -6°C | 65 mm | 9.5 | 0.4°C | 10 h 30 | 5 | Strong coverage |
| March | 7.6°C | -2.1°C | 68 mm | 9.4 | 1.3°C | 11 h 48 | 5 | Strong coverage |
| April | 14.6°C | 3.5°C | 94 mm | 11.3 | 5.0°C | 13 h 18 | 33 | Strong coverage |
| May | 21.4°C | 9.8°C | 95 mm | 11.1 | 11.3°C | 14 h 33 | 66 | Strong coverage |
| June | 26.8°C | 15.6°C | 80 mm | 9.2 | 17.7°C | 15 h 14 | 78 | Strong coverage |
| July | 29°C | 18.1°C | 91 mm | 8.9 | 22.1°C | 14 h 58 | 65 | Strong coverage |
| August | 27.8°C | 17.4°C | 84 mm | 8.4 | 22.9°C | 13 h 53 | 71 | Strong coverage |
| September | 24°C | 13.5°C | 96 mm | 8.4 | 20.1°C | 12 h 26 | 84 | Strong coverage |
| October | 16.6°C | 7.3°C | 75 mm | 9 | 13.9°C | 10 h 59 | 51 | Strong coverage |
| November | 8.8°C | 1.3°C | 73 mm | 9.5 | 8.4°C | 9 h 44 | 14 | Good coverage |
| December | 2.9°C | -3.6°C | 63 mm | 9.9 | 4.1°C | 9 h 07 | 5 | Good coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 15.0°C14 Jan 1995 | -28.0°C19 Jan 1994 | 47 mm27 Jan 1994 | 133 mm2024 · driest 18 mm in 2022 | 34 |
| February | 20.5°C23 Feb 2017 | -22.5°C10 Feb 1994 | 53 mm22 Feb 1990 | 125 mm1990 · driest 12 mm in 1989 | 32 |
| March | 26.5°C27 Mar 2007 | -20.5°C3 Mar 2003 | 44 mm8 Mar 1998 | 136 mm2016 · driest 2 mm in 2013 | 33 |
| April | 30.0°C25 Apr 1990 | -8.5°C5 Apr 2016 | 60 mm20 Apr 2000 | 139 mm1999 · driest 28 mm in 2008 | 35 |
| May | 33.5°C29 May 2018 | -2.0°C4 May 2005 | 68 mm30 May 2015 | 206 mm2015 · driest 18 mm in 2013 | 34 |
| June | 36.0°C25 Jun 2005 | 5.0°C1 Jun 2003 | 57 mm20 Jun 2021 | 174 mm2015 · driest 23 mm in 2011 | 35 |
| July | 38.5°C17 Jul 2012 | 8.0°C2 Jul 2001 | 89 mm19 Jul 1989 | 198 mm1989 · driest 23 mm in 2007 | 36 |
| August | 37.0°C17 Aug 1988 | 8.0°C6 Aug 1994 | 93 mm23 Aug 2023 | 187 mm2007 · driest 11 mm in 2010 | 36 |
| September | 35.0°C2 Sep 2011 | 1.0°C30 Sep 1993 | 117 mm6 Sep 1990 | 187 mm1990 · driest 23 mm in 2023 | 35 |
| October | 31.5°C1 Oct 2019 | -5.0°C31 Oct 1988 | 53 mm25 Oct 1991 | 168 mm2021 · driest 20 mm in 2022 | 34 |
| November | 24.0°C1 Nov 2016 | -11.0°C13 Nov 2019 | 48 mm30 Nov 2006 | 161 mm2017 · driest 5 mm in 2007 | 31 |
| December | 18.0°C3 Dec 1998 | -22.5°C22 Dec 1989 | 42 mm29 Dec 1990 | 143 mm1990 · driest 24 mm in 1995 | 30 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 24 | 2 | 6 |
| February | 0 | 0 | 23 | 2 | 5 |
| March | <1 | 0 | 20 | 2 | 3 |
| April | 2 | 0 | 7 | 3 | 1 |
| May | 8 | 2 | <1 | 3 | 0 |
| June | 19 | 7 | 0 | 3 | 0 |
| July | 25 | 11 | 0 | 3 | 0 |
| August | 24 | 8 | 0 | 3 | 0 |
| September | 12 | 3 | 0 | 3 | 0 |
| October | 2 | <1 | 2 | 2 | 0 |
| November | 0 | 0 | 12 | 3 | 2 |
| December | 0 | 0 | 23 | 2 | 4 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 0% | 36% | 6% | 41% | -3.0–4.0°C |
| February | 0% | 32% | 7% | 35% | -0.8–5.5°C |
| March | 3% | 31% | 8% | 42% | 5.0–11.2°C |
| April | 13% | 38% | 10% | 54% | 12.3–16.7°C |
| May | 38% | 34% | 10% | 42% | 18.7–23.9°C |
| June | 67% | 30% | 10% | 35% | 25.2–28.5°C |
| July | 71% | 29% | 10% | 35% | 27.1–31.3°C |
| August | 72% | 27% | 10% | 25% | 25.7–29.7°C |
| September | 60% | 27% | 10% | 30% | 22.1–25.7°C |
| October | 21% | 30% | 8% | 31% | 14.8–18.8°C |
| November | 2% | 31% | 8% | 40% | 5.7–12.0°C |
| December | 0% | 33% | 7% | 42% | 0.1–6.3°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