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Weather & Climate in Unalaska, AK
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Unalaska has a cool climate with an average annual temperature of 42°F (5°C). Winters average 33°F in January while summers reach 52°F in July / relatively mild seasonal variation. The area gets 166 sunny days per year, below the national average of 205. Annual precipitation totals 60.1 inches (wetter than the 38-inch national average). The area receives 81.6 inches of snow annually, making winter weather a significant factor for residents. Air quality is rated Good with a median AQI of 21 / among the cleanest air in the country. The city sits at an elevation of 1,062 feet.
Temperature
33°F Jan (1°C)
52°F Jul (11°C)
| Annual Average | 41.6°F |
| 23% below US avg | |
| January Average | 33°F (1°C) |
| July Average | 52°F (11°C) |
| Sunny Days | 166 days/yr |
Geography
| Elevation | 1,062 ft (324 m) |
| Area | 212.7 sq mi (550.8 km²) |
| Population Density | 43/sq mi |
| Coordinates | 53.9103°N, 166.5290°W |
| Timezone | America/Anchorage |
| Nearest Airport | Ted Stevens Anchorage International (ANC) 788 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 21.0 |
| Rating | Good |
Earthquake History
4,486 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M6.6.
| Feb 19, 2003 | 92 km SE of Akutan, Alaska | M6.6 | 127 km | 19 km |
| Oct 13, 2009 | 127 km E of Nikolski, Alaska | M6.5 | 132 km | 24 km |
| Jan 22, 2022 | 71 km S of Unalaska, Alaska | M6.2 | 75 km | 29 km |
| Feb 13, 1992 | 59 km S of Akutan, Alaska | M6.0 | 63 km | 44 km |
| Jan 26, 2025 | 86 km SSW of Unalaska, Alaska | M5.6 | 90 km | 59 km |
| Aug 8, 1996 | 97 km SSW of Unalaska, Alaska | M5.5 | 102 km | 44 km |
| May 9, 2001 | 110 km ESE of Akutan, Alaska | M5.5 | 148 km | 42 km |
| Oct 15, 2009 | 114 km S of Unalaska, Alaska | M5.5 | 119 km | 20 km |
| Mar 1, 2002 | 131 km S of Unalaska, Alaska | M5.5 | 135 km | 33 km |
| Jul 9, 2019 | 92 km E of Nikolski, Alaska | M5.5 | 129 km | 33 km |
| Oct 19, 1991 | 48 km WSW of Unalaska, Alaska | M5.4 | 50 km | 33 km |
| May 25, 2000 | 125 km ESE of Nikolski, Alaska | M5.4 | 146 km | 33 km |
| Sep 14, 2019 | 16 km SSW of Akutan, Alaska | M5.4 | 46 km | 67 km |
| May 11, 1999 | 65 km SSE of Akutan, Alaska | M5.4 | 82 km | 51 km |
| Oct 20, 1991 | 26 km WSW of Dutch Harbor, Alaska | M5.4 | 28 km | 33 km |
| Jul 26, 2016 | 116 km S of Unalaska, Alaska | M5.4 | 121 km | 17 km |
| Oct 5, 2024 | 85 km SSW of Unalaska, Alaska | M5.4 | 90 km | 41 km |
| Apr 4, 1993 | 112 km SE of Akutan, Alaska | M5.4 | 142 km | 33 km |
| Jan 10, 2007 | 81 km WSW of Dutch Harbor, Alaska | M5.3 | 83 km | 28 km |
| Aug 1, 2022 | 67 km SSE of Akutan, Alaska | M5.3 | 82 km | 40 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tsunami History
1 tsunami recorded within 500 km. Highest wave on record: 0.1 m (0 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1965 | FOX ISLANDS, ALEUTIAN ISLANDS, AK | Earthquake | 0.1 m | — | 119 km |
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
8 volcanoes within 200 km. Closest: Makushin (26 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Makushin | Stratovolcano | 1,800 m (5,906 ft) | 1995 | 26 km |
| Akutan | Stratovolcano | 1,303 m (4,275 ft) | 1992 | 43 km |
| Bogoslof | Submarine | 150 m (492 ft) | 2017 | 98 km |
| Okmok | Shield | 1,073 m (3,520 ft) | 2008 | 118 km |
| Westdahl | Stratovolcano? | 1,563 m (5,128 ft) | 1992 | 140 km |
| Recheschnoi | Stratovolcano | 1,984 m (6,509 ft) | Unknown | 157 km |
| Fisher | Stratovolcano | 1,112 m (3,648 ft) | 1830 | 159 km |
| Shishaldin | Stratovolcano | 2,857 m (9,373 ft) | 2020 | 191 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 33°F (1°C) | 6.0 in | |
| February | 30°F (-1°C) | 6.6 in | Coldest |
| March | 31°F (-1°C) | 5.3 in | |
| April | 33°F (1°C) | 4.3 in | |
| May | 38°F (3°C) | 4.8 in | |
| June | 44°F (7°C) | 3.1 in | |
| July | 52°F (11°C) | 2.3 in | Warmest, Driest |
| August | 51°F (10°C) | 2.7 in | |
| September | 46°F (8°C) | 5.7 in | |
| October | 39°F (4°C) | 8.0 in | Wettest |
| November | 34°F (1°C) | 6.9 in | |
| December | 32°F (-0°C) | 6.7 in |
Unalaska has a seasonal temperature swing of 22°F / from 30°F in February to 52°F in July. Total annual precipitation is 62.4 inches, with October being the wettest month (8.0") and July the driest (2.3").