United States · 1991–2020

Best time to visit
Unalaska.

August leads for comfortable weather in Unalaska: typically 15.1°C by day, 8.9°C at night, with 72 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortAugust

Typical high15.1°C

Typical low8.9°C

Rain in August72 mm

Comfort

August

August · July · June

47climate match

Beach

August

August · July · January

10climate match

Outdoors

July

July · August · June

68climate match

The weakest month is January, scoring 5 against August’s 47 — days reach only 3°C, 21° 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

53° / -1.8°

Feb

53.8° / -1.3°

Mar

53.9° / -1.4°

Apr

55.4° / 0.3°

May

98.1° / 3.1°

Jun

3111.2° / 5.8°

Jul

4614° / 8.1°

Aug

4715.1° / 8.9°

Sep

2012.5° / 6.8°

Oct

58.9° / 3.6°

Nov

56.3° / 0.7°

Dec

54.1° / -0.7°

Monthly climate evidence for Unalaska — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 27 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	3°C	-1.8°C	172 mm	17.3	4.4°C	7 h 56	5	Strong coverage
February	3.8°C	-1.3°C	145 mm	15.7	3.9°C	9 h 40	5	Strong coverage
March	3.9°C	-1.4°C	119 mm	14.5	3.7°C	11 h 39	5	Strong coverage
April	5.4°C	0.3°C	86 mm	13.1	3.9°C	13 h 56	5	Strong coverage
May	8.1°C	3.1°C	98 mm	12.3	5.0°C	15 h 55	9	Strong coverage
June	11.2°C	5.8°C	63 mm	9.8	6.9°C	17 h 05	31	Strong coverage
July	14°C	8.1°C	57 mm	8.9	8.6°C	16 h 37	46	Strong coverage
August	15.1°C	8.9°C	72 mm	10.8	9.7°C	14 h 50	47	Strong coverage
September	12.5°C	6.8°C	143 mm	16.3	9.0°C	12 h 37	20	Strong coverage
October	8.9°C	3.6°C	200 mm	20.5	7.8°C	10 h 26	5	Strong coverage
November	6.3°C	0.7°C	169 mm	17.5	6.6°C	8 h 27	5	Strong coverage
December	4.1°C	-0.7°C	201 mm	18.5	5.4°C	7 h 26	5	Strong coverage

Records at DUTCH HARBOR, 1915–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	14.4°C11 Jan 1952	-22.2°C22 Jan 1986	102 mm18 Jan 1991	432 mm1991 · driest 9 mm in 1983	74
February	15.6°C5 Feb 1932	-17.8°C5 Feb 1991	193 mm5 Feb 1947	364 mm1940 · driest 0 mm in 2022	73
March	20.6°C25 Mar 1936	-16.7°C14 Mar 1983	69 mm18 Mar 2024	376 mm1999 · driest 1 mm in 2022	72
April	16.1°C14 Apr 1935	-12.2°C13 Apr 1983	88 mm2 Apr 1936	205 mm1936 · driest 0 mm in 2022	75
May	18.9°C27 May 1927	-9.4°C2 May 1984	93 mm9 May 1941	282 mm1937 · driest 0 mm in 2022	76
June	22.8°C21 Jun 1915	-1.1°C6 Jun 1916	76 mm26 Jun 1923	212 mm1920 · driest 0 mm in 2022	76
July	26.1°C9 Jul 1917	1.1°C12 Jul 1989	122 mm20 Jul 2003	186 mm2003 · driest 0 mm in 2021	77
August	27.8°C28 Aug 1982	-3.9°C4 Aug 1986	61 mm16 Aug 1990	158 mm1997 · driest 0 mm in 2021	75
September	26.7°C10 Sep 1939	-5.0°C5 Sep 1993	61 mm23 Sep 1939	303 mm2011 · driest 0 mm in 2021	73
October	18.3°C1 Oct 1916	-15.0°C29 Oct 1985	138 mm25 Oct 2019	460 mm2002 · driest 0 mm in 2021	74
November	19.4°C21 Nov 1926	-13.3°C30 Nov 1991	173 mm16 Nov 1946	499 mm2000 · driest 2 mm in 2021	71
December	15.0°C8 Dec 1994	-15.0°C27 Dec 1989	91 mm1 Dec 2008	485 mm1994 · driest 0 mm in 2021	73

Typical days per month at DUTCH HARBOR, 1991–2020
Month	Days 25°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	20	5	10
February	0	17	5	8
March	0	21	4	8
April	0	13	2	4
May	0	3	3	<1
June	0	<1	2	0
July	0	0	2	0
August	<1	<1	2	0
September	0	<1	5	0
October	0	4	6	<1
November	0	11	5	4
December	0	18	6	9

How often, not how much — every day in DUTCH HARBOR’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%	54%	16%	75%	0.5–4.6°C
February	0%	56%	16%	73%	0.9–5.3°C
March	<1%	46%	11%	63%	1.9–5.6°C
April	0%	45%	8%	62%	3.6–6.4°C
May	0%	40%	9%	55%	6.3–9.2°C
June	<1%	31%	6%	38%	9.8–12.3°C
July	4%	27%	4%	31%	12.7–15.2°C
August	6%	33%	5%	45%	13.4–16.3°C
September	<1%	51%	14%	73%	10.6–13.8°C
October	0%	61%	18%	85%	7.2–9.7°C
November	0%	59%	15%	82%	3.8–7.6°C
December	0%	60%	18%	82%	2.3–5.8°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.

1916Each stripe is one year’s mean temperature against the 55-year average. Warmest: 2016. Coolest: 1916.2023

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5877208
NOAA station: USC00502587 · DUTCH HARBOR
Station distance: 2.4 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 28 usable years
Daylight: Calculated from latitude 53.87°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 27 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 DUTCH HARBOR is what differs

Dutch Harbor→Akutan→Cheerful (historical)→Chernofski→Imagnee (historical)→Kashega→

Or put two places side by side: Unalaska vs Dutch Harbor

Best time to visitUnalaska.

August

August

July

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Unalaska.

The whole year,
without the guesswork.

Nearby, measured,
and named.