Photo: John Bortniak · Public domainPetersburg gets about 86 inches of snow a winter, more than 96% of U.S. towns
July afternoons average 62°. Summers stay cool: July afternoons here are cooler than in almost every U.S. town. Seasons differ by 35°, from the coldest nights to the warmest afternoons. The frost-free window for a garden runs roughly April 29 to October 17.
A year in Petersburg at a glance
Each month’s typical high and low, and what it brings.
What stands out about Petersburg’s climate
Compared with towns across the U.S., with Petersburg’s place in Alaska beside it.
What a year in Petersburg feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 169 frost-free days a year
In half of years the last 32° night comes by April 29 and the first by October 17. Frost and day counts come from Petersburg 1, AK, 4 miles away.
The 2023 USDA map puts Petersburg’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 2°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
About 86 inches of snow a winter
Snow, measured at Petersburg 1, AK, falls mostly in January and March. Precipitation (rain plus melted snow) adds up to 110 inches a year; September is the wettest month and June the driest. Rain or snow falls on about 229 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Petersburg
Nearly all of the work is heating: a normal year has almost no cooling days. Months averaging under 55° run from September through June.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Petersburg 1, AK.
Living with Petersburg’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
169 frost-free days in zone 7a. The last frost comes by Apr 29 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 17.
22 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Petersburg from natural hazards, landslides are the largest share (60%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Petersburg and similar climates
TownRatings has no climate map of the towns around Petersburg yet.
Climates most like Petersburg’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Petersburg, AK | 27° | 62° | 110" | 86" |
| Lincoln City, OR | 40° | 67° | 88" | 0.1" |
| Hoquiam, WA | 37° | 68° | 81" | 0.5" |
| Crescent City, CA | 42° | 64° | 69" | 0.0" |
| North Elba, NY | 4° | 72° | 52" | 104" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
How Petersburg compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Petersburg’s place among Alaska’s.
Petersburg weather by month
Highs, lows and precipitation from the nearest NOAA station; snow, wet days and snow on the ground from Petersburg 1, AK. 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" | 0.0" | 16 | 0 |
| July | 62° | 51° | 5.6" | 0.0" | 17 | 0 |
| August | 61° | 50° | 8.2" | 0.0" | 17 | 0 |
| September | 56° | 46° | 14.4" | 0.0" | 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 |
Where Petersburg’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s 1991–2020 normals at the nearest station (NOAA’s grid doesn’t cover Alaska).
- Snow: Petersburg 1, AK.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Petersburg 1, AK, 4 miles from the town’s center, 710 ft lower; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Petersburg’s climate
What is the weather like in Petersburg?
A typical July afternoon reaches 62°, a January night drops to 27°, and about 86 inches of snow falls in a normal winter. Milder January nights than 68% of U.S. towns; cooler July afternoons than all but 6 U.S. towns.
How cold does it get in Petersburg in winter?
January nights average 27°. About 115 nights a year reach 32° or below and 1 reach 0° or below.
How much snow does Petersburg get?
About 86 inches in a normal winter at Petersburg 1, AK, most of it in January and March, with snow on the ground about 66 days a year.
How hot does it get in Petersburg?
July, with a typical high of 62°. 90° days are rare: none in a normal year at Petersburg 1, AK.
When is the first and last frost in Petersburg?
In half of years the last spring frost (32°) comes by April 29 and the first fall frost by October 17, about 169 frost-free days, at Petersburg 1, AK.
What growing zone is Petersburg in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 2°.
What is the best time of year to visit Petersburg?
No month meets the simple rule we use (highs of 62–84° and lows of 40° or more). The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Neighbors talk weather
Gardens, snow, and the best days of the year in Petersburg.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.