United States · 1991–2020

Best time to visit
Iowa City.

September leads for comfortable weather in Iowa City: typically 25.1°C by day, 11.9°C at night, with 78 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.1°C

Typical low11.9°C

Rain in September78 mm

Comfort

September

September · May · August

82climate match

Beach

July

July · August · June

77climate match

Outdoors

October

October · May · September

72climate match

The weakest month is January, scoring 5 against September’s 82 — days reach only -0.8°C, 25° 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

5-0.8° / -10.1°

Feb

51.6° / -8.2°

Mar

149.2° / -2°

Apr

4316.7° / 4°

May

7022.5° / 10.5°

Jun

6727.6° / 16.2°

Jul

6529.5° / 18.3°

Aug

7028.5° / 17°

Sep

8225.1° / 11.9°

Oct

5117.4° / 5°

Nov

199.4° / -1.4°

Dec

51.8° / -7.3°

Monthly climate evidence for Iowa City — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-0.8°C	-10.1°C	22 mm	4.3	9 h 28	5	Strong coverage
February	1.6°C	-8.2°C	33 mm	5.1	10 h 32	5	Strong coverage
March	9.2°C	-2°C	54 mm	6.8	11 h 48	14	Strong coverage
April	16.7°C	4°C	91 mm	8.9	13 h 16	43	Strong coverage
May	22.5°C	10.5°C	116 mm	9.6	14 h 30	70	Strong coverage
June	27.6°C	16.2°C	126 mm	9.6	15 h 11	67	Strong coverage
July	29.5°C	18.3°C	88 mm	6.7	14 h 55	65	Strong coverage
August	28.5°C	17°C	94 mm	7.1	13 h 51	70	Strong coverage
September	25.1°C	11.9°C	78 mm	6.5	12 h 25	82	Strong coverage
October	17.4°C	5°C	77 mm	6.8	11 h 01	51	Strong coverage
November	9.4°C	-1.4°C	44 mm	5.4	9 h 46	19	Strong coverage
December	1.8°C	-7.3°C	36 mm	5.1	9 h 10	5	Strong coverage

Records at IOWA CITY MUNI AP, 1948–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	18.3°C8 Jan 2003	-33.3°C31 Jan 1996	36 mm25 Jan 1950	84 mm1950 · driest 1 mm in 1948	37
February	25.0°C27 Feb 2024	-36.7°C3 Feb 1996	42 mm27 Feb 1948	103 mm2001 · driest 4 mm in 2026	37
March	32.8°C21 Mar 2026	-26.7°C12 Mar 1948	43 mm8 Mar 2009	141 mm1951 · driest 10 mm in 2003	37
April	33.3°C29 Apr 1952	-9.3°C2 Apr 2018	101 mm17 Apr 2013	215 mm2013 · driest 17 mm in 2018	37
May	36.7°C28 May 2018	-4.4°C3 May 2005	119 mm9 May 1996	300 mm1996 · driest 41 mm in 2006	37
June	37.2°C27 Jun 2012	5.0°C4 Jun 1950	144 mm22 Jun 2007	249 mm2014 · driest 24 mm in 1997	36
July	40.6°C25 Jul 2012	7.8°C5 Jul 1997	77 mm3 Jul 2004	201 mm1948 · driest 7 mm in 2012	36
August	38.3°C30 Aug 2013	4.4°C20 Aug 1950	85 mm23 Aug 2002	212 mm2018 · driest 2 mm in 2013	36
September	38.3°C9 Sep 2013	-3.3°C23 Sep 1995	70 mm5 Sep 2018	190 mm2019 · driest 1 mm in 2024	36
October	33.9°C3 Oct 2006	-11.7°C29 Oct 1952	90 mm17 Oct 1998	184 mm2009 · driest 0 mm in 1952	36
November	26.1°C1 Nov 2000	-19.4°C24 Nov 1950	67 mm16 Nov 1952	147 mm1952 · driest 1 mm in 1997	36
December	23.9°C15 Dec 2021	-28.3°C15 Dec 1951	40 mm13 Dec 2015	88 mm2015 · driest 4 mm in 1995	36

Typical days per month at IOWA CITY MUNI AP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	0	0	29	<1
February	0	0	26	<1
March	<1	0	21	2
April	4	<1	7	3
May	12	2	<1	4
June	23	10	0	4
July	29	15	0	3
August	27	11	0	3
September	17	6	<1	3
October	4	<1	6	2
November	<1	0	19	1
December	0	0	28	1

How often, not how much — every day in IOWA CITY MUNI 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	0%	15%	2%	8%	-3.6–1.4°C
February	<1%	18%	4%	14%	-3.4–5.9°C
March	8%	24%	7%	23%	5.3–13.1°C
April	25%	29%	10%	35%	13.5–19.5°C
May	52%	30%	11%	37%	20.6–25.1°C
June	67%	31%	12%	37%	26.2–29.8°C
July	76%	23%	11%	22%	27.8–31.6°C
August	78%	22%	9%	19%	27.0–30.2°C
September	72%	19%	8%	19%	22.7–27.5°C
October	34%	20%	7%	20%	15.0–20.4°C
November	6%	17%	5%	13%	5.2–12.3°C
December	<1%	18%	4%	12%	-1.7–5.7°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.

1948Each stripe is one year’s mean temperature against the 35-year average. Warmest: 2024. Coolest: 1951.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4862034
NOAA station: USW00014937 · IOWA CITY MUNI AP
Station distance: 2.7 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 25 usable years
Daylight: Calculated from latitude 41.66°, 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 IOWA CITY MUNI AP is what differs

Coralville→North Liberty→Tiffin→Solon→University Heights→Frytown→

Or put two places side by side: Iowa City vs Coralville

Best time to visitIowa City.