Weather & Climate in Mill Bay, AK
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Mill Bay has a cool climate with an average annual temperature of 42°F (6°C). Winters average 32°F in January while summers reach 55°F in July. Annual precipitation totals 75.6 inches (wetter than the 38-inch national average). The area receives 42.9 inches of snow annually, making winter weather a significant factor for residents. The city sits at an elevation of 110 feet.
Temperature
32°F Jan (-0°C)
55°F Jul (13°C)
| Annual Average | 41.9°F |
| 22% below US avg | |
| January Average | 32°F (-0°C) |
| July Average | 55°F (13°C) |
Geography
| Elevation | 110 ft (34 m) |
| Area | 3.4 sq mi (8.9 km²) |
| Population Density | 1,029/sq mi |
| Coordinates | 57.8155°N, 152.3675°W |
| Timezone | America/Anchorage |
| County | Kodiak Island Borough County |
| Nearest Airport | Ted Stevens Anchorage International (ANC) 246 miles away |
Precipitation & Snow
Air Quality
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 65.1 / 100 |
| Social Vulnerability | 33.2 / 100 |
| Community Resilience | 18.7 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Very Low |
| Hail | No Rating |
| Strong Wind | No Rating |
| Winter Weather | Relatively Low |
| Lightning | Very Low |
| Ice Storm | Very Low |
| Drought | No Rating |
| Cold Wave | No Rating |
| Landslide | Relatively Moderate |
| Coastal Flood | No Rating |
| Tsunami | Relatively Moderate |
| Volcano | Very Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
2,397 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M7.0.
| Dec 6, 1999 | 26 km SSE of Karluk, Alaska | M7.0 | 129 km | 44 km |
| Jan 10, 2001 | 47 km S of Old Harbor, Alaska | M6.9 | 128 km | 36 km |
| Jul 11, 2000 | 24 km SSW of Larsen Bay, Alaska | M6.5 | 121 km | 43 km |
| Dec 7, 1999 | 29 km N of Akhiok, Alaska | M6.4 | 132 km | 44 km |
| Jul 19, 2001 | 107 km SE of Chiniak, Alaska | M5.9 | 126 km | 36 km |
| May 27, 2019 | 61 km SSW of Nanwalek, Alaska | M5.8 | 116 km | 64 km |
| May 19, 2000 | 63 km WSW of Nanwalek, Alaska | M5.8 | 143 km | 75 km |
| Nov 8, 1998 | 101 km SE of Old Harbor, Alaska | M5.7 | 146 km | 10 km |
| Mar 8, 1990 | 35 km N of Aleneva, Alaska | M5.6 | 72 km | 73 km |
| Aug 31, 2017 | 61 km NW of Aleneva, Alaska | M5.6 | 103 km | 63 km |
| Jul 11, 2000 | 23 km SSE of Karluk, Alaska | M5.5 | 123 km | 38 km |
| Jan 20, 2004 | 82 km ENE of Ouzinkie, Alaska | M5.5 | 81 km | 46 km |
| Feb 21, 2023 | 43 km SSE of Old Harbor, Alaska | M5.4 | 116 km | 12 km |
| Dec 1, 2012 | 81 km WNW of Aleneva, Alaska | M5.4 | 123 km | 85 km |
| May 11, 2017 | 69 km SE of Old Harbor, Alaska | M5.4 | 119 km | 10 km |
| Mar 8, 2000 | 27 km SW of Larsen Bay, Alaska | M5.4 | 124 km | 40 km |
| Mar 27, 2008 | 41 km SSW of Nanwalek, Alaska | M5.3 | 133 km | 69 km |
| Jan 10, 2001 | 55 km S of Old Harbor, Alaska | M5.3 | 138 km | 32 km |
| Dec 6, 1999 | 33 km N of Akhiok, Alaska | M5.3 | 124 km | 42 km |
| Jan 2, 2009 | 62 km NNE of Ouzinkie, Alaska | M5.3 | 69 km | 64 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tsunami History
3 tsunamis recorded within 500 km. Highest wave on record: 30.0 m (98 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1788 | ALASKA PENINSULA, AK | Earthquake | 30.0 m | - | 98 km |
| 1854 | KODIAK ISLAND, AK | Eruption + Earthquake | 2.4 m | - | 93 km |
| 1970 | ANDREANOF ISLANDS, AK | Earthquake | 0.0 m | - | 98 km |
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
4 volcanoes within 200 km. Closest: Katmai (161 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Katmai | Stratovolcano | 2,047 m (6,716 ft) | 1912 | 161 km |
| Trident | Stratovolcano | 1,864 m (6,115 ft) | 1974 | 168 km |
| Martin | Stratovolcano | 1,863 m (6,112 ft) | 1953 | 181 km |
| Augustine | Lava dome(s) | 1,252 m (4,108 ft) | 2006 | 183 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
1 wildfire (100+ acres) recorded within 100 km. Largest: TWIN CREEKS (3,418 acres, 2015).
| Year | Name | Acres Burned | Distance |
| 2015 | TWIN CREEKS | 3,418 | 24 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 32°F (-0°C) | 7.9 in | Coldest |
| February | 33°F (0°C) | 6.0 in | |
| March | 33°F (1°C) | 5.1 in | |
| April | 39°F (4°C) | 5.6 in | |
| May | 45°F (7°C) | 5.4 in | |
| June | 50°F (10°C) | 5.1 in | |
| July | 55°F (13°C) | 4.5 in | Driest |
| August | 56°F (13°C) | 5.0 in | Warmest |
| September | 50°F (10°C) | 7.3 in | |
| October | 42°F (6°C) | 8.3 in | Wettest |
| November | 36°F (2°C) | 7.1 in | |
| December | 33°F (0°C) | 8.3 in |
Mill Bay has a seasonal temperature swing of 24°F / from 32°F in January to 56°F in August. Total annual precipitation is 75.6 inches, with October being the wettest month (8.3") and July the driest (4.5").