United States · 1991–2020

Best time to visit
Duluth.

August leads for comfortable weather in Duluth: typically 23.8°C by day, 14.4°C at night, with 100 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortAugust

Typical high23.8°C

Typical low14.4°C

Rain in August100 mm

Comfort

August

August · July · September

85climate match

Beach

July

July · August · September

52climate match

Outdoors

September

September · June · August

83climate match

The weakest month is January, scoring 5 against August’s 85 — days reach only -5.3°C, 29° 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

5-5.3° / -14.5°

Feb

5-2.6° / -12.3°

Mar

52.2° / -6.1°

Apr

107.7° / -0.3°

May

3614.1° / 4.9°

Jun

5919.5° / 9.8°

Jul

8324.6° / 14.5°

Aug

8523.8° / 14.4°

Sep

6419.2° / 10.1°

Oct

2811.7° / 3.7°

Nov

54° / -3.5°

Dec

5-2.6° / -10.5°

Monthly climate evidence for Duluth — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 20 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	-5.3°C	-14.5°C	22 mm	5.3	2.1°C	8 h 55	5	Strong coverage
February	-2.6°C	-12.3°C	23 mm	4.2	1.3°C	10 h 13	5	Strong coverage
March	2.2°C	-6.1°C	39 mm	5.4	1.3°C	11 h 45	5	Strong coverage
April	7.7°C	-0.3°C	66 mm	7.2	2.0°C	13 h 30	10	Strong coverage
May	14.1°C	4.9°C	86 mm	9.4	3.3°C	15 h 00	36	Strong coverage
June	19.5°C	9.8°C	113 mm	9.7	6.4°C	15 h 50	59	Strong coverage
July	24.6°C	14.5°C	99 mm	8.4	12.9°C	15 h 30	83	Strong coverage
August	23.8°C	14.4°C	100 mm	8	16.9°C	14 h 12	85	Strong coverage
September	19.2°C	10.1°C	86 mm	8.1	14.5°C	12 h 29	64	Strong coverage
October	11.7°C	3.7°C	80 mm	7.9	9.8°C	10 h 48	28	Strong coverage
November	4°C	-3.5°C	54 mm	6.4	6.0°C	9 h 18	5	Strong coverage
December	-2.6°C	-10.5°C	33 mm	5.5	3.6°C	8 h 33	5	Strong coverage

What has changed

Duluth runs +0.4°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

+1.7

Feb

+0.8

Mar

+0.9

Apr

-1.7

May

-0.9

Jun

-0.7

Jul

+0.3

Aug

+0.4

Sep

+1.1

Oct

-0.1

Nov

+0.6

Dec

+1.8

August daytime highs, 2011–2025. Last recorded: 24.3°C.

Records at SUPERIOR, 1909–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	12.8°C24 Jan 1942	-38.3°C29 Jan 1951	27 mm2 Jan 1941	80 mm1969 · driest 2 mm in 1963	116
February	15.6°C22 Feb 1961	-38.9°C12 Feb 1967	34 mm24 Feb 1977	69 mm1922 · driest 1 mm in 1968	115
March	26.7°C28 Mar 1946	-38.9°C1 Mar 1962	72 mm12 Mar 1977	213 mm1977 · driest 0 mm in 2026	114
April	33.3°C28 Apr 1952	-18.9°C3 Apr 1954	91 mm15 Apr 1961	196 mm2001 · driest 6 mm in 1987	115
May	35.6°C31 May 1939	-11.7°C3 May 1967	77 mm29 May 1913	209 mm2012 · driest 7 mm in 1976	118
June	36.7°C18 Jun 1995	-3.9°C1 Jun 1964	111 mm20 Jun 2012	311 mm2012 · driest 8 mm in 1910	116
July	40.6°C14 Jul 1936	1.1°C8 Jul 1961	146 mm1 Jul 1958	254 mm1952 · driest 15 mm in 1936	115
August	37.2°C24 Aug 1948	-0.6°C20 Aug 1950	109 mm9 Aug 1939	226 mm2010 · driest 5 mm in 1930	114
September	36.1°C8 Sep 1976	-7.2°C13 Sep 1963	105 mm22 Sep 1924	215 mm1991 · driest 7 mm in 2020	115
October	31.7°C2 Oct 1992	-12.8°C30 Oct 1925	101 mm3 Oct 2005	203 mm2005 · driest 0 mm in 1953	116
November	26.1°C6 Nov 2020	-28.3°C28 Nov 1976	61 mm25 Nov 1993	122 mm1983 · driest 0 mm in 1916	117
December	15.6°C1 Dec 1962	-35.6°C28 Dec 1917	46 mm5 Dec 1909	110 mm2019 · driest 1 mm in 1999	116

Typical days per month at SUPERIOR, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	30	<1	7
February	0	0	27	<1	5
March	0	0	26	1	4
April	<1	0	14	2	2
May	2	<1	2	3	0
June	7	1	0	3	0
July	16	6	0	3	0
August	13	3	0	3	0
September	4	<1	<1	3	0
October	<1	<1	7	2	<1
November	0	0	22	2	3
December	0	0	29	<1	6

How often, not how much — every day in SUPERIOR’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%	16%	2%	11%	-9.8–-2.4°C
February	0%	14%	2%	11%	-7.5–0.1°C
March	<1%	17%	4%	15%	-1.4–5.1°C
April	5%	23%	7%	26%	5.4–11.9°C
May	19%	29%	10%	36%	12.0–17.7°C
June	40%	32%	11%	40%	18.1–23.4°C
July	63%	26%	9%	28%	22.6–27.3°C
August	60%	26%	10%	29%	21.9–26.2°C
September	33%	27%	9%	31%	16.6–20.9°C
October	11%	22%	6%	22%	9.8–14.9°C
November	<1%	20%	4%	18%	0.8–6.8°C
December	0%	17%	2%	13%	-7.1–0.3°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.

1910Each stripe is one year’s mean temperature against the 96-year average. Warmest: 2024. Coolest: 1917.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5024719
NOAA station: USC00478349 · SUPERIOR
Station distance: 6.8 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 27 usable years
Daylight: Calculated from latitude 46.78°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 20 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 SUPERIOR is what differs

Superior→Superior Village→Oliver→Bayview→Clifton→Fond du Lac→

Or put two places side by side: Duluth vs Superior

Best time to visitDuluth.