United States · 1991–2020

Best time to visit
Washington Park.

September leads for comfortable weather in Washington Park: typically 27.6°C by day, 13.9°C at night, with 82 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high27.6°C

Typical low13.9°C

Rain in September82 mm

Comfort

September

September · May · October

77climate match

Beach

August

August · July · June

75climate match

Outdoors

October

October · April · September

81climate match

The weakest month is January, scoring 5 against September’s 77 — days reach only 5.1°C, 19° below the 24°C the score treats as ideal.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan

55.1° / -4.6°

Feb

87.5° / -2.9°

Mar

3113.6° / 2°

Apr

5820.1° / 7.5°

May

7425.2° / 13.4°

Jun

5730.1° / 18°

Jul

5331.9° / 20.1°

Aug

6031° / 18.7°

Sep

7727.6° / 13.9°

Oct

6720.9° / 7.7°

Nov

3313.6° / 1.9°

Dec

56.9° / -2.6°

Monthly climate evidence for Washington Park — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	5.1°C	-4.6°C	62 mm	5.4	9 h 44	5	Good coverage
February	7.5°C	-2.9°C	53 mm	5.9	10 h 41	8	Good coverage
March	13.6°C	2°C	84 mm	8.3	11 h 50	31	Good coverage
April	20.1°C	7.5°C	109 mm	8.8	13 h 09	58	Good coverage
May	25.2°C	13.4°C	122 mm	10.5	14 h 15	74	Good coverage
June	30.1°C	18°C	125 mm	8.3	14 h 51	57	Good coverage
July	31.9°C	20.1°C	98 mm	6.9	14 h 37	53	Good coverage
August	31°C	18.7°C	85 mm	6.3	13 h 40	60	Good coverage
September	27.6°C	13.9°C	82 mm	5.4	12 h 23	77	Good coverage
October	20.9°C	7.7°C	80 mm	6.7	11 h 07	67	Good coverage
November	13.6°C	1.9°C	74 mm	6.6	10 h 01	33	Good coverage
December	6.9°C	-2.6°C	62 mm	6.6	9 h 29	5	Good coverage

Records at CAHOKIA ST LOUIS DWTN AP, 1997–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	22.2°C6 Jan 2008	-25.5°C7 Jan 2014	52 mm4 Jan 2004	208 mm2005 · driest 7 mm in 2003	29
February	30.0°C27 Feb 2024	-21.6°C7 Feb 2014	57 mm24 Feb 2018	154 mm2018 · driest 4 mm in 2006	29
March	33.9°C22 Mar 2026	-15.5°C3 Mar 2014	69 mm18 Mar 2008	220 mm2008 · driest 1 mm in 2005	29
April	33.3°C14 Apr 2006	-4.3°C7 Apr 2007	80 mm18 Apr 2013	250 mm2025 · driest 43 mm in 2018	29
May	35.0°C26 May 2012	0.6°C4 May 2011	60 mm16 May 2020	233 mm2024 · driest 32 mm in 2012	29
June	41.7°C28 Jun 2012	7.2°C7 Jun 2000	122 mm26 Jun 1999	293 mm2015 · driest 22 mm in 2024	30
July	41.7°C6 Jul 2012	10.0°C28 Jul 2013	184 mm26 Jul 2022	305 mm2024 · driest 22 mm in 2012	30
August	40.6°C15 Aug 2007	8.3°C12 Aug 2004	88 mm15 Aug 2016	191 mm2016 · driest 4 mm in 2020	29
September	38.9°C1 Sep 2011	1.7°C26 Sep 2000	121 mm8 Sep 2018	197 mm2018 · driest 4 mm in 2004	29
October	34.4°C1 Oct 2019	-5.5°C25 Oct 2013	72 mm25 Oct 2022	276 mm2009 · driest 16 mm in 2024	29
November	29.4°C1 Nov 2016	-11.6°C12 Nov 2019	82 mm4 Nov 2024	213 mm2024 · driest 9 mm in 1999	29
December	25.6°C28 Dec 2025	-20.6°C20 Dec 2000	56 mm26 Dec 2015	215 mm2015 · driest 12 mm in 2025	29

Typical days per month at CAHOKIA ST LOUIS DWTN AP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	0	0	25	2
February	<1	0	20	2
March	2	0	12	3
April	7	1	3	4
May	18	7	0	4
June	27	17	0	4
July	30	23	0	3
August	30	21	0	3
September	22	10	0	2
October	9	2	3	3
November	1	0	13	2
December	0	0	22	2

How often, not how much — every day in CAHOKIA ST LOUIS DWTN AP’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	2%	17%	7%	12%	2.8–8.3°C
February	5%	19%	6%	20%	2.8–11.5°C
March	19%	26%	10%	29%	11.1–18.4°C
April	39%	30%	14%	37%	18.2–22.9°C
May	58%	33%	14%	41%	23.2–27.1°C
June	73%	26%	12%	33%	28.6–32.0°C
July	77%	23%	11%	22%	30.1–33.6°C
August	80%	21%	9%	17%	29.7–32.4°C
September	79%	18%	8%	16%	25.6–29.5°C
October	49%	21%	9%	23%	18.8–23.2°C
November	16%	22%	8%	21%	9.9–16.0°C
December	2%	22%	7%	22%	4.2–10.1°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.

1998Each stripe is one year’s mean temperature against the 28-year average. Warmest: 2024. Coolest: 2014.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4252512
NOAA station: USW00003960 · CAHOKIA ST LOUIS DWTN AP
Station distance: 9.3 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 22 usable years
Daylight: Calculated from latitude 38.64°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from CAHOKIA ST LOUIS DWTN AP is what differs

East Saint Louis→Collinsville→Fairview Heights→Centreville→Caseyville→Millstadt→

Or put two places side by side: Washington Park vs East Saint Louis

Best time to visitWashington Park.