United States · 1991–2020

Best time to visit
Merrionette Park.

September leads for comfortable weather in Merrionette Park: typically 24.5°C by day, 14.8°C at night, with 85 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high24.5°C

Typical low14.8°C

Rain in September85 mm

Comfort

September

September · June · May

87climate match

Beach

July

July · August · June

79climate match

Outdoors

October

October · May · September

71climate match

The weakest month is January, scoring 5 against September’s 87 — days reach only 0.2°C, 24° 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

50.2° / -7.2°

Feb

52.5° / -5.3°

Mar

128.6° / -0.3°

Apr

3715.3° / 5.2°

May

6721.7° / 11.1°

Jun

7027.1° / 16.8°

Jul

6029.4° / 19.8°

Aug

6528.2° / 19.1°

Sep

8724.5° / 14.8°

Oct

5217.4° / 8°

Nov

199.5° / 1.5°

Dec

53° / -4°

Monthly climate evidence for Merrionette Park — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 22 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	0.2°C	-7.2°C	58 mm	8.2	3.3°C	9 h 28	5	Strong coverage
February	2.5°C	-5.3°C	54 mm	7.1	2.0°C	10 h 32	5	Strong coverage
March	8.6°C	-0.3°C	67 mm	8.4	2.0°C	11 h 48	12	Strong coverage
April	15.3°C	5.2°C	105 mm	10	3.8°C	13 h 16	37	Strong coverage
May	21.7°C	11.1°C	121 mm	10.4	7.1°C	14 h 30	67	Strong coverage
June	27.1°C	16.8°C	115 mm	9.5	14.1°C	15 h 11	70	Strong coverage
July	29.4°C	19.8°C	102 mm	7.9	20.9°C	14 h 55	60	Strong coverage
August	28.2°C	19.1°C	104 mm	8	22.5°C	13 h 51	65	Strong coverage
September	24.5°C	14.8°C	85 mm	7	20.1°C	12 h 25	87	Strong coverage
October	17.4°C	8°C	98 mm	8.7	14.5°C	11 h 01	52	Strong coverage
November	9.5°C	1.5°C	69 mm	7.6	9.2°C	9 h 46	19	Strong coverage
December	3°C	-4°C	59 mm	8	5.6°C	9 h 10	5	Strong coverage

What has changed

Merrionette Park runs +1.1°C
on the 1961–1990 baseline.

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.

Jan

+1.8

Feb

+1.3

Mar

+1.6

Apr

+0.2

May

+0.6

Jun

+0.9

Jul

+0.6

Aug

+0.7

Sep

+1.3

Oct

+0.4

Nov

+0.5

Dec

+2.7

September daytime highs, 2011–2025. Last recorded: 26.6°C.

Records at CHICAGO MIDWAY AP 3SW, 1928–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	19.4°C25 Jan 1950	-31.7°C20 Jan 1985	70 mm12 Jan 1960	135 mm2005 · driest 3 mm in 1981	98
February	23.9°C27 Feb 1976	-28.9°C9 Feb 1933	83 mm21 Feb 1997	172 mm1997 · driest 5 mm in 2026	98
March	30.0°C29 Mar 1986	-21.7°C8 Mar 1943	64 mm31 Mar 1929	172 mm2009 · driest 8 mm in 1958	99
April	33.3°C30 Apr 1942	-12.2°C7 Apr 1982	97 mm18 Apr 1975	212 mm1947 · driest 12 mm in 1971	98
May	38.9°C31 May 1934	-2.2°C12 May 1981	100 mm17 May 2020	227 mm2019 · driest 6 mm in 1992	99
June	41.7°C1 Jun 1934	1.7°C4 Jun 1945	118 mm13 Jun 1976	331 mm1993 · driest 20 mm in 1956	99
July	41.1°C13 Jul 1995	7.8°C5 Jul 1972	157 mm12 Jul 1957	283 mm2023 · driest 1 mm in 2026	85
August	38.9°C2 Aug 1991	6.1°C29 Aug 1965	115 mm22 Aug 2014	253 mm1987 · driest 19 mm in 1996	84
September	38.3°C2 Sep 1953	-1.7°C28 Sep 1942	106 mm11 Sep 2000	360 mm1961 · driest 0 mm in 1979	84
October	34.4°C6 Oct 1963	-6.7°C18 Oct 1948	130 mm14 Oct 2017	307 mm1954 · driest 5 mm in 1964	98
November	27.2°C1 Nov 1950	-19.4°C28 Nov 1930	89 mm10 Nov 1995	194 mm1985 · driest 14 mm in 1976	97
December	22.2°C3 Dec 2012	-28.9°C24 Dec 1983	71 mm2 Dec 1982	183 mm1982 · driest 8 mm in 1962	98

Typical days per month at CHICAGO MIDWAY AP 3SW, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	27	2	9
February	0	0	23	2	6
March	<1	0	18	2	4
April	3	<1	4	4	<1
May	10	4	0	4	0
June	21	10	0	4	0
July	27	15	0	3	0
August	26	10	0	3	0
September	15	5	0	2	0
October	4	<1	1	3	<1
November	<1	0	12	2	2
December	0	0	24	2	6

How often, not how much — every day in CHICAGO MIDWAY AP 3SW’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	0%	24%	5%	26%	-3.9–3.3°C
February	<1%	23%	5%	23%	-2.2–6.0°C
March	5%	28%	7%	35%	4.5–11.7°C
April	18%	32%	10%	41%	12.5–17.7°C
May	43%	31%	11%	38%	18.5–24.5°C
June	66%	29%	12%	35%	24.9–29.2°C
July	74%	25%	11%	27%	27.5–31.1°C
August	76%	24%	10%	22%	26.3–30.1°C
September	63%	23%	9%	25%	22.6–26.6°C
October	29%	24%	8%	26%	15.2–20.0°C
November	5%	25%	7%	29%	6.0–11.9°C
December	<1%	25%	6%	25%	-1.4–5.8°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.

1942Each stripe is one year’s mean temperature against the 83-year average. Warmest: 2024. Coolest: 1979.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4902033
NOAA station: USC00111577 · CHICAGO MIDWAY AP 3SW
Station distance: 8.7 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 30 usable years
Daylight: Calculated from latitude 41.68°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 22 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
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 CHICAGO MIDWAY AP 3SW is what differs

Orland Park→Oak Lawn→Burbank→Blue Island→Morgan Park→Evergreen Park→

Or put two places side by side: Merrionette Park vs Orland Park

Best time to visitMerrionette Park.