Unalaska, AK climate
Unalaska has mild, snowy winters and cool summers, with plenty of rain. A typical July afternoon reaches 57°, a January night drops to 29°, and about 82 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decade3° cooler than normal today. The forecast high is 48°, and a typical Oct 1 in Unalaska peaks around 51°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in Unalaska feels like
Winter
Spring
Summer
Fall
Unalaska weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground |
|---|---|---|---|---|---|---|
| January | 37° | 29° | 6.8" | 22.0" | 22 | 17 |
| February | 39° | 29° | 5.2" | 14.2" | 19 | 14 |
| March | 39° | 29° | 4.7" | 16.5" | 19 | 14 |
| April | 42° | 33° | 3.5" | 6.3" | 18 | 7 |
| May | 47° | 37° | 4.2" | 0.2" | 18 | 0 |
| June | 52° | 42° | 2.5" | 0 | 15 | 0 |
| July | 57° | 47° | 2.3" | 0 | 14 | 0 |
| August | 59° | 48° | 2.9" | 0 | 15 | 0 |
| September | 55° | 44° | 5.7" | 0 | 20 | 0 |
| October | 48° | 38° | 7.9" | 0.4" | 25 | 0 |
| November | 43° | 33° | 6.7" | 6.2" | 23 | 5 |
| December | 39° | 31° | 7.9" | 15.8" | 23 | 13 |
| Year | 46° | 37° | 60.1" | 81.6" | 231 | 70 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more.
Rain and snow in Unalaska
Unalaska gets 60 inches of rain and melted snow a year. October is the wettest month and July the driest. Rain or snow falls on about 231 days a year. Snow covers the ground about 70 days of the year.
About 164 frost-free days a year
In half of years the last 32° night comes by May 6 and the first one by October 18. That leaves about 164 frost-free days for gardens, shorter than 67% of U.S. towns.
Heating and cooling a home in Unalaska
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Unalaska, 100% of that work is heating and 0% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Unalaska compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Common questions about Unalaska’s climate
What is the coldest month in Unalaska?
January, with a typical high of 37° and a low of 29°.
What is the hottest month in Unalaska?
August, with a typical high of 59° and a low of 48°.
How much snow does Unalaska get?
About 82 inches in a normal winter, most of it in January.
When is the first frost in Unalaska?
In half of years the first 32° night comes by October 18, and the last spring frost by May 6.
What is the rainiest month in Unalaska?
October, with 7.9 inches of rain and melted snow. The year totals 60 inches.
NOAA’s gridded normals don’t cover this state, so temperatures and rainfall come from the nearest weather station. Snow, frost dates and day counts come from NOAA’s weather station at Dutch Harbor, AK (1 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020.