United States · 1991–2020

Best time to visit
Grand Chain.

May leads for comfortable weather in Grand Chain: typically 24.6°C by day, 13.4°C at night, with 129 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortMay

Typical high24.6°C

Typical low13.4°C

Rain in May129 mm

Comfort

May

May · September · October

76climate match

Beach

August

August · July · September

80climate match

Outdoors

October

October · April · May

78climate match

The weakest month is January, scoring 5 against May’s 76 — days reach only 6.1°C, 18° 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

56.1° / -3.3°

Feb

58.1° / -1.7°

Mar

2613.8° / 2.8°

Apr

5620° / 8.3°

May

7624.6° / 13.4°

Jun

6029.5° / 18.2°

Jul

5431.3° / 20.2°

Aug

6031.2° / 19.7°

Sep

7628° / 15.7°

Oct

6821.5° / 9.1°

Nov

3114° / 3.1°

Dec

58° / -0.9°

Monthly climate evidence for Grand Chain — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	6.1°C	-3.3°C	101 mm	7.8	9 h 51	5	Strong coverage
February	8.1°C	-1.7°C	94 mm	7.7	10 h 45	5	Strong coverage
March	13.8°C	2.8°C	125 mm	9.1	11 h 51	26	Strong coverage
April	20°C	8.3°C	130 mm	8.7	13 h 06	56	Strong coverage
May	24.6°C	13.4°C	129 mm	9.8	14 h 09	76	Good coverage
June	29.5°C	18.2°C	119 mm	8.3	14 h 43	60	Good coverage
July	31.3°C	20.2°C	100 mm	6.6	14 h 29	54	Good coverage
August	31.2°C	19.7°C	73 mm	6.1	13 h 35	60	Good coverage
September	28°C	15.7°C	83 mm	5.9	12 h 22	76	Good coverage
October	21.5°C	9.1°C	105 mm	6.4	11 h 10	68	Good coverage
November	14°C	3.1°C	110 mm	7.4	10 h 07	31	Strong coverage
December	8°C	-0.9°C	112 mm	8.4	9 h 37	5	Strong coverage

Records at OLMSTED L&D, 1923–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	21.7°C16 Jan 1928	-20.0°C5 Jan 1924	114 mm24 Jan 2002	230 mm1927 · driest 25 mm in 2026	37
February	24.4°C21 Feb 2017	-22.2°C19 Feb 2015	83 mm16 Feb 2025	216 mm2019 · driest 6 mm in 2026	36
March	27.2°C22 Mar 2012	-18.3°C7 Mar 2015	152 mm19 Mar 2008	284 mm2008 · driest 35 mm in 2007	36
April	31.7°C24 Apr 1925	-9.4°C3 Apr 2000	163 mm4 Apr 2008	354 mm2011 · driest 21 mm in 2012	36
May	35.6°C22 May 1925	1.7°C4 May 2011	76 mm2 May 2011	296 mm2024 · driest 12 mm in 2012	36
June	40.0°C30 Jun 2012	6.1°C7 Jun 2000	89 mm1 Jun 2013	359 mm1928 · driest 23 mm in 2023	36
July	40.6°C20 Jul 2012	10.6°C4 Jul 1924	170 mm20 Jul 2023	364 mm2023 · driest 9 mm in 2018	37
August	40.0°C19 Aug 1925	10.0°C13 Aug 2000	66 mm30 Aug 2003	196 mm1926 · driest 7 mm in 1925	36
September	42.2°C6 Sep 1925	2.2°C26 Sep 1928	97 mm28 Sep 2024	215 mm1925 · driest 0 mm in 2004	35
October	34.4°C3 Oct 2019	-5.0°C29 Oct 1925	133 mm18 Oct 2007	262 mm2009 · driest 1 mm in 1924	35
November	26.7°C9 Nov 2020	-11.1°C18 Nov 2014	109 mm1 Nov 2018	250 mm2011 · driest 6 mm in 2023	36
December	23.3°C26 Dec 2021	-22.2°C24 Dec 2022	117 mm17 Dec 2001	247 mm2015 · driest 20 mm in 1925	37

Typical days per month at OLMSTED L&D, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	21	3	1
February	0	0	16	3	1
March	<1	0	10	4	<1
April	5	<1	1	4	0
May	15	4	0	4	0
June	26	15	0	4	0
July	29	21	0	4	0
August	28	20	0	2	0
September	22	10	0	2	0
October	9	1	<1	3	0
November	<1	0	9	3	<1
December	0	0	17	4	<1

How often, not how much — every day in OLMSTED L&D’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	<1%	26%	12%	26%	3.3–8.6°C
February	2%	26%	10%	27%	4.3–12.4°C
March	14%	28%	12%	33%	10.8–17.7°C
April	37%	30%	13%	37%	18.0–22.3°C
May	61%	31%	13%	35%	22.7–26.7°C
June	72%	27%	13%	28%	27.0–31.4°C
July	77%	21%	9%	18%	29.9–33.1°C
August	79%	20%	9%	19%	29.2–32.8°C
September	79%	21%	9%	22%	26.5–30.2°C
October	53%	20%	9%	20%	19.3–24.0°C
November	14%	25%	11%	26%	10.5–16.7°C
December	2%	26%	11%	30%	6.2–11.7°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.

1924Each stripe is one year’s mean temperature against the 30-year average. Warmest: 2024. Coolest: 2014.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4239675
NOAA station: USC00113580 · OLMSTED L&D
Station distance: 8.4 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 22 usable years
Daylight: Calculated from latitude 37.25°, 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 OLMSTED L&D is what differs

La Center→Karnak→Tamms→Ullin→Olmsted→Cypress→

Or put two places side by side: Grand Chain vs La Center

Best time to visitGrand Chain.

May

August

October

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Grand Chain.

The whole year,
without the guesswork.

Nearby, measured,
and named.