Petersburg, AK climate
Petersburg has chilly, snowy winters and cool summers, with plenty of rain. A typical July afternoon reaches 62°, a January night drops to 27°, and about 86 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Petersburg feels like
Winter
Spring
Summer
Fall
Petersburg 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 | 35° | 27° | 11.4" | 20.7" | 21 | 18 |
| February | 37° | 28° | 7.6" | 16.9" | 17 | 15 |
| March | 40° | 30° | 7.6" | 20.0" | 20 | 13 |
| April | 48° | 35° | 6.7" | 1.1" | 18 | 1 |
| May | 55° | 42° | 5.9" | 0.2" | 16 | 0 |
| June | 60° | 48° | 5.0" | 0 | 16 | 0 |
| July | 62° | 51° | 5.6" | 0 | 17 | 0 |
| August | 61° | 50° | 8.2" | 0 | 17 | 0 |
| September | 56° | 46° | 14.4" | 0 | 20 | 0 |
| October | 47° | 39° | 13.8" | 0.4" | 23 | 0 |
| November | 39° | 32° | 12.3" | 10.8" | 23 | 5 |
| December | 35° | 28° | 11.8" | 15.5" | 21 | 14 |
| Year | 48° | 38° | 110.2" | 85.6" | 229 | 66 |
“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 Petersburg
Petersburg gets 110 inches of rain and melted snow a year. September is the wettest month and June the driest. Rain or snow falls on about 229 days a year. Snow covers the ground about 66 days of the year.
About 169 frost-free days a year
In half of years the last 32° night comes by April 29 and the first one by October 17. That leaves about 169 frost-free days for gardens, shorter than 62% of U.S. towns.
Heating and cooling a home in Petersburg
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Petersburg, 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 Petersburg compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Common questions about Petersburg’s climate
What is the coldest month in Petersburg?
January, with a typical high of 35° and a low of 27°.
What is the hottest month in Petersburg?
July, with a typical high of 62° and a low of 51°.
How much snow does Petersburg get?
About 86 inches in a normal winter, most of it in January.
When is the first frost in Petersburg?
In half of years the first 32° night comes by October 17, and the last spring frost by April 29.
What is the rainiest month in Petersburg?
September, with 14.4 inches of rain and melted snow. The year totals 110 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 Petersburg 1, AK (4 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020.