United States · 1991–2020

Best time to visit
Decorah.

September leads for comfortable weather in Decorah: typically 24.2°C by day, 10.5°C at night, with 92 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high24.2°C

Typical low10.5°C

Rain in September92 mm

Comfort

September

September · August · July

79climate match

Beach

July

July · August · June

67climate match

Outdoors

September

September · October · May

71climate match

The weakest month is January, scoring 5 against September’s 79 — days reach only -2.8°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

5-2.8° / -12.8°

Feb

50.1° / -10.7°

Mar

67.4° / -4.1°

Apr

3415.7° / 2.2°

May

6222° / 8.4°

Jun

6427° / 14°

Jul

6728.7° / 16.3°

Aug

7227.7° / 15.2°

Sep

7924.2° / 10.5°

Oct

4816.9° / 3.9°

Nov

97.6° / -2.8°

Dec

50.1° / -8.9°

Monthly climate evidence for Decorah — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-2.8°C	-12.8°C	28 mm	4.9	9 h 18	5	Strong coverage
February	0.1°C	-10.7°C	26 mm	4.5	10 h 26	5	Strong coverage
March	7.4°C	-4.1°C	50 mm	6.5	11 h 47	6	Strong coverage
April	15.7°C	2.2°C	101 mm	9.7	13 h 21	34	Strong coverage
May	22°C	8.4°C	122 mm	11.3	14 h 39	62	Strong coverage
June	27°C	14°C	156 mm	10.9	15 h 22	64	Strong coverage
July	28.7°C	16.3°C	112 mm	8.2	15 h 05	67	Strong coverage
August	27.7°C	15.2°C	111 mm	8.2	13 h 57	72	Strong coverage
September	24.2°C	10.5°C	92 mm	7.7	12 h 27	79	Strong coverage
October	16.9°C	3.9°C	68 mm	7.2	10 h 57	48	Strong coverage
November	7.6°C	-2.8°C	51 mm	5.9	9 h 38	9	Strong coverage
December	0.1°C	-8.9°C	34 mm	5.7	8 h 59	5	Strong coverage

What has changed

Decorah runs +1.8°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

+2.6

Feb

+1.6

Mar

+2.9

Apr

+0.7

May

+1.1

Jun

+1.6

Jul

+0.7

Aug

+0.9

Sep

+2.9

Oct

+1.7

Nov

+2.0

Dec

+3.5

September daytime highs, 2011–2025. Last recorded: 26.3°C.

Records at DECORAH, 1893–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	16.7°C30 Jan 2025	-41.7°C30 Jan 1951	32 mm25 Jan 1967	95 mm1996 · driest 2 mm in 2025	125
February	23.3°C26 Feb 2024	-40.6°C3 Feb 1996	49 mm22 Feb 1922	101 mm1915 · driest 0 mm in 1987	124
March	29.4°C29 Mar 2025	-36.1°C1 Mar 1962	58 mm14 Mar 1913	120 mm1913 · driest 0 mm in 1999	126
April	33.9°C22 Apr 1980	-15.0°C6 Apr 1982	95 mm23 Apr 1968	222 mm2008 · driest 14 mm in 2021	126
May	38.9°C31 May 1934	-6.7°C3 May 1908	95 mm4 May 2018	308 mm2004 · driest 20 mm in 1897	124
June	40.6°C29 Jun 1910	-1.7°C1 Jun 1897	168 mm8 Jun 2008	358 mm2008 · driest 1 mm in 1910	124
July	43.9°C14 Jul 1936	3.3°C14 Jul 1926	154 mm29 Jul 1970	275 mm2022 · driest 6 mm in 1937	125
August	40.6°C24 Aug 2023	0.0°C30 Aug 1915	220 mm18 Aug 2025	384 mm2007 · driest 8 mm in 1969	125
September	37.8°C1 Sep 1913	-7.8°C30 Sep 1899	122 mm21 Sep 1986	296 mm2016 · driest 8 mm in 1979	123
October	34.4°C6 Oct 1963	-21.7°C30 Oct 1925	78 mm10 Oct 1904	151 mm2017 · driest 1 mm in 1952	125
November	26.1°C6 Nov 1893	-26.7°C28 Nov 1930	67 mm10 Nov 1975	202 mm1909 · driest 0 mm in 1976	125
December	20.6°C15 Dec 2021	-37.8°C27 Dec 1950	39 mm14 Dec 2015	122 mm2015 · driest 2 mm in 1998	125

Typical days per month at DECORAH, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	30	<1	6
February	0	0	27	<1	5
March	<1	0	24	1	3
April	3	<1	11	4	1
May	10	2	2	4	0
June	22	7	0	5	0
July	28	12	0	3	0
August	25	8	0	4	0
September	15	4	<1	3	0
October	3	<1	9	2	0
November	0	0	21	2	2
December	0	0	29	<1	6

The best month has moved. On the 1961–1990 numbers the strongest month here was June (scoring 79); on 2011–2025 it is September (80). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in DECORAH’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%	10%	-7.1–0.2°C
February	<1%	14%	2%	7%	-5.3–3.7°C
March	4%	20%	5%	18%	2.0–9.8°C
April	20%	28%	10%	34%	11.5–18.1°C
May	47%	33%	12%	41%	19.5–24.7°C
June	64%	33%	14%	41%	24.4–29.5°C
July	75%	25%	10%	24%	26.8–32.0°C
August	74%	25%	10%	25%	25.8–30.8°C
September	58%	26%	10%	30%	21.2–26.3°C
October	28%	21%	7%	19%	13.6–19.6°C
November	3%	18%	5%	15%	3.1–10.5°C
December	0%	16%	3%	10%	-4.6–3.4°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.

1895Each stripe is one year’s mean temperature against the 116-year average. Warmest: 2024. Coolest: 1917.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4853608
NOAA station: USC00132110 · DECORAH
Station distance: 0.8 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 29 usable years
Daylight: Calculated from latitude 43.30°, 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 DECORAH is what differs

Calmar→Ossian→Mabel→Spillville→Fort Atkinson→Burr Oak→

Or put two places side by side: Decorah vs Calmar

Best time to visitDecorah.

September

July

September

The whole year,without the guesswork.

Decorah runs +1.8°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Decorah.

The whole year,
without the guesswork.

Decorah runs +1.8°C
on the 1961–1990 baseline.

Nearby, measured,
and named.