United States · 1991–2020

Best time to visit
Grundy Center.

September leads for comfortable weather in Grundy Center: typically 23.9°C by day, 10.3°C at night, with 83 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high23.9°C

Typical low10.3°C

Rain in September83 mm

Comfort

September

September · August · June

81climate match

Beach

July

July · August · June

67climate match

Outdoors

September

September · May · October

75climate match

The weakest month is January, scoring 5 against September’s 81 — days reach only -3.3°C, 27° 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

5-3.3° / -12.9°

Feb

5-0.7° / -10.7°

Mar

56.7° / -4.3°

Apr

3214.9° / 2°

May

6121.3° / 9.1°

Jun

6826.7° / 15.3°

Jul

6828.2° / 16.9°

Aug

7427.2° / 15.3°

Sep

8123.9° / 10.3°

Oct

4716.6° / 3.6°

Nov

97.5° / -3.2°

Dec

50.1° / -9.4°

Monthly climate evidence for Grundy Center — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-3.3°C	-12.9°C	21 mm	4.3	9 h 24	5	Strong coverage
February	-0.7°C	-10.7°C	27 mm	4.5	10 h 29	5	Strong coverage
March	6.7°C	-4.3°C	48 mm	5.9	11 h 48	5	Strong coverage
April	14.9°C	2°C	98 mm	9.1	13 h 18	32	Strong coverage
May	21.3°C	9.1°C	124 mm	10.6	14 h 34	61	Strong coverage
June	26.7°C	15.3°C	151 mm	10.2	15 h 16	68	Strong coverage
July	28.2°C	16.9°C	113 mm	7.7	14 h 59	68	Strong coverage
August	27.2°C	15.3°C	112 mm	7.8	13 h 54	74	Strong coverage
September	23.9°C	10.3°C	83 mm	6.9	12 h 26	81	Strong coverage
October	16.6°C	3.6°C	71 mm	6.6	10 h 59	47	Strong coverage
November	7.5°C	-3.2°C	47 mm	5.2	9 h 43	9	Strong coverage
December	0.1°C	-9.4°C	35 mm	5.2	9 h 05	5	Strong coverage

What has changed

Grundy Center runs +0.8°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

+1.3

Feb

+0.2

Mar

+1.6

Apr

-0.1

May

0.0

Jun

+0.8

Jul

-0.3

Aug

0.0

Sep

+1.9

Oct

+0.6

Nov

+0.7

Dec

+2.9

September daytime highs, 2011–2025. Last recorded: 26.1°C.

Records at GRUNDY CTR, 1893–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	18.9°C27 Jan 2002	-35.6°C12 Jan 1912	76 mm4 Jan 1922	127 mm1922 · driest 0 mm in 1948	134
February	24.4°C27 Feb 2024	-36.7°C13 Feb 1905	36 mm25 Feb 2007	78 mm1971 · driest 0 mm in 1923	133
March	31.7°C29 Mar 1895	-33.3°C1 Mar 1962	152 mm3 Mar 1924	451 mm1924 · driest 0 mm in 1919	133
April	35.6°C23 Apr 1980	-18.3°C4 Apr 1975	112 mm25 Apr 2008	298 mm2008 · driest 4 mm in 1934	133
May	41.1°C31 May 1934	-6.7°C4 May 1907	93 mm30 May 2013	345 mm2013 · driest 14 mm in 1934	132
June	41.1°C27 Jun 1934	1.7°C3 Jun 1946	142 mm10 Jun 1900	373 mm1947 · driest 28 mm in 2021	133
July	41.7°C13 Jul 1936	4.4°C17 Jul 1911	159 mm10 Jul 2000	334 mm2010 · driest 2 mm in 1894	134
August	42.2°C18 Aug 1936	2.8°C20 Aug 1950	133 mm27 Aug 1923	334 mm1923 · driest 6 mm in 1984	131
September	38.3°C7 Sep 1939	-6.7°C30 Sep 1899	116 mm18 Sep 1900	296 mm1941 · driest 7 mm in 2024	131
October	34.4°C4 Oct 1997	-20.6°C30 Oct 1925	98 mm4 Oct 1919	187 mm2017 · driest 1 mm in 1952	132
November	26.7°C14 Nov 1999	-25.6°C26 Nov 1977	76 mm4 Nov 2003	193 mm1931 · driest 0 mm in 1976	132
December	22.8°C3 Dec 1998	-32.8°C26 Dec 1914	81 mm13 Dec 2015	208 mm2015 · driest 3 mm in 1962	131

Typical days per month at GRUNDY CTR, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	31	<1	5
February	0	0	27	<1	4
March	<1	0	24	2	2
April	2	<1	11	3	<1
May	10	2	1	4	0
June	21	7	0	5	0
July	26	10	0	4	0
August	24	7	0	4	0
September	14	4	<1	3	0
October	3	<1	9	2	<1
November	<1	0	22	2	2
December	0	0	29	<1	4

The best month has moved. On the 1961–1990 numbers the strongest month here was August (scoring 80); on 2011–2025 it is September (85). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in GRUNDY CTR’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%	14%	2%	8%	-7.1–1.7°C
February	<1%	15%	3%	8%	-4.9–4.0°C
March	5%	20%	6%	18%	2.2–10.7°C
April	21%	28%	10%	33%	12.1–18.1°C
May	45%	32%	12%	39%	19.2–24.4°C
June	65%	32%	14%	36%	24.5–29.1°C
July	76%	24%	11%	25%	27.0–31.9°C
August	75%	24%	10%	24%	26.0–30.6°C
September	61%	24%	10%	25%	21.6–26.4°C
October	32%	20%	7%	19%	14.5–20.4°C
November	4%	17%	5%	13%	4.3–11.1°C
December	<1%	15%	3%	9%	-3.8–4.0°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.

1893Each stripe is one year’s mean temperature against the 119-year average. Warmest: 1931. Coolest: 1893.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4859430
NOAA station: USC00133487 · GRUNDY CTR
Station distance: 0.8 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 30 usable years
Daylight: Calculated from latitude 42.36°, 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 GRUNDY CTR is what differs

Reinbeck→Dike→Holland→Stout→Lincoln→Morrison→

Or put two places side by side: Grundy Center vs Reinbeck

Best time to visitGrundy Center.

September

July

September

The whole year,without the guesswork.

Grundy Center runs +0.8°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Grundy Center.

The whole year,
without the guesswork.

Grundy Center runs +0.8°C
on the 1961–1990 baseline.

Nearby, measured,
and named.