All Countries
Weather & Climate in St. Mary's, AK
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
St. Mary's has a cool climate with an average annual temperature of 31°F (-0°C). Winters average 7°F in January while summers reach 56°F in July. The area gets 274 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 19.7 inches (drier than the 38-inch national average). The area receives 64.0 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 486 feet.
Temperature
7°F Jan (-14°C)
56°F Jul (14°C)
| Annual Average | 31.4°F |
| 42% below US avg | |
| January Average | 7°F (-14°C) |
| July Average | 56°F (14°C) |
| Sunny Days | 274 days/yr |
Geography
| Elevation | 486 ft (148 m) |
| Area | 44.6 sq mi (115.5 km²) |
| Population Density | 18/sq mi |
| Coordinates | 62.0628°N, 163.2443°W |
| Timezone | America/Anchorage |
| County | Kusilvak Census Area County |
| Nearest Airport | Ted Stevens Anchorage International (ANC) 439 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 21.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 57.9 / 100 |
| Social Vulnerability | 100.0 / 100 |
| Community Resilience | 5.9 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | No Rating |
| Hail | Very Low |
| Strong Wind | Very Low |
| Winter Weather | Relatively Moderate |
| Lightning | Very Low |
| Ice Storm | Very Low |
| Drought | No Rating |
| Cold Wave | Relatively High |
| Landslide | Relatively Low |
| Coastal Flood | No Rating |
| Volcano | Very Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
8 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.0.
| Jan 16, 2006 | 10 km NE of Nunam Iqua, Alaska | M3.0 | 95 km | 15 km |
| Mar 21, 2005 | 23 km WNW of Emmonak, Alaska | M2.9 | 123 km | 10 km |
| Oct 31, 2017 | 33 km ESE of Emmonak, Alaska | M2.8 | 77 km | 8 km |
| Mar 7, 2024 | 71 km N of Marshall, Alaska | M2.8 | 83 km | 15 km |
| Jan 23, 2025 | 30 km SSE of Nunam Iqua, Alaska | M2.7 | 76 km | 2 km |
| Apr 13, 2008 | 27 km E of Kotlik, Alaska | M2.7 | 110 km | 19 km |
| Jul 17, 2025 | 42 km SSW of Nunam Iqua, Alaska | M2.6 | 97 km | 19 km |
| Jun 17, 2019 | 18 km S of Willow Creek, Alaska | M2.6 | 86 km | 9 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Nearby Volcanoes
1 volcano within 200 km. Closest: St. Michael (165 km).
| Name | Type | Elevation | Last Eruption | Distance |
| St. Michael | Shield(s) | 715 m (2,346 ft) | Unknown | 165 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: EAST FORK (169,506 acres, 2022).
| Year | Name | Acres Burned | Distance |
| 2022 | EAST FORK | 169,506 | 26 km |
| 2022 | APOON PASS | 89,373 | 52 km |
| 2015 | KUKA CREEK 4 | 70,232 | 91 km |
| 2020 | INGAKSLUGWAT HILLS | 69,482 | 95 km |
| 2006 | NAGEETHLUK RIVER | 56,332 | 85 km |
| 2020 | KOCHILAGOK HILL | 29,730 | 78 km |
| 2015 | IZAVLKNEK RIVER | 23,341 | 88 km |
| 2002 | AROPUK | 19,915 | 85 km |
| 2009 | ALLMAN LAKE | 17,514 | 77 km |
| 1991 | 132242 | 14,334 | 70 km |
| 1984 | KUYUKUTUK | 8,479 | 84 km |
| 2009 | NAGEETHLUK RIVER | 5,852 | 81 km |
| 2019 | KUYUKUTUK RIVER | 5,175 | 89 km |
| 2020 | IZAVIKNEK RIVER | 3,728 | 73 km |
| 2022 | PONGLEVIK RIVER | 3,261 | 65 km |
| 2007 | NOYUK | 3,003 | 77 km |
| 2017 | ALLEN | 2,501 | 54 km |
| 2007 | KUKA | 2,488 | 84 km |
| 2020 | ENGINEER LAKE 2 | 1,844 | 88 km |
| 2020 | KGUN LAKE | 1,691 | 63 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 7°F (-14°C) | 0.9 in | Coldest |
| February | 9°F (-13°C) | 0.8 in | |
| March | 13°F (-11°C) | 0.8 in | |
| April | 24°F (-5°C) | 0.7 in | Driest |
| May | 39°F (4°C) | 1.0 in | |
| June | 51°F (10°C) | 1.7 in | |
| July | 56°F (14°C) | 2.4 in | Warmest |
| August | 53°F (12°C) | 4.2 in | Wettest |
| September | 45°F (7°C) | 3.2 in | |
| October | 31°F (-1°C) | 1.7 in | |
| November | 18°F (-8°C) | 1.4 in | |
| December | 9°F (-13°C) | 1.1 in |
St. Mary's has a seasonal temperature swing of 49°F / from 7°F in January to 56°F in July. Total annual precipitation is 19.8 inches, with August being the wettest month (4.2") and April the driest (0.7").