Frost dates by state › Alaska
Alaska frost dates
Average last spring and first fall frost dates for Alaska’s largest cities, with each city’s USDA hardiness zone.
Reviewed October 2026
Among Alaska’s 20 largest cities, the average last spring frost ranges from Apr 4 in Ketchikan to Jun 11 in Soldotna. Elevation, distance from the coast and city heat all shift the date, so use your own ZIP code below for the closest match.
In Utqiaġvik, the nearest weather station can record a freeze in any month, so pick fast, cold-tolerant crops and keep covers ready.
| City | Average last spring frost | Average first fall frost | Frost-free days | Hardiness zone | Weather station used |
|---|---|---|---|---|---|
| Anchorage | May 16 | Sep 20 | 127 | 5a | Eagle Rvr Nature Ctr, AK, 4 mi |
| Fairbanks | May 16 | Sep 6 | 113 | 2a–2b | Aurora, AK, 2 mi |
| Juneau | May 3 | Oct 14 | 164 | 6a | Annex Creek, AK, 5 mi |
| Wasilla | May 16 | Sep 23 | 130 | 5a | Anderson Lake, AK, 5 mi |
| Sitka | May 3 | Oct 18 | 168 | 7b | Sitka 1 Ne, AK, 9 mi |
| Ketchikan | Apr 4 | Nov 9 | 219 | 8a | Beaver Falls, AK |
| Kenai | May 24 | Sep 12 | 111 | 4b | Kenai Muni Airport, AK, 2 mi |
| Palmer | May 6 | Sep 25 | 142 | 5a | Palmer Muni Airport, AK |
| Bethel | May 21 | Sep 22 | 124 | 4a | Bethel Airport, AK |
| Homer | May 10 | Sep 29 | 142 | 6a | Homer Airport, AK |
| Kodiak | Apr 29 | Oct 14 | 168 | 7b | Kodiak Wwtp, AK, 3 mi |
| Utqiaġvik | Any month | Any month | – | 2b | Barrow Post Rogers Airport, AK |
| Soldotna | Jun 11 | Sep 1 | 82 | 4b | Soldotna 5Ssw, AK, 5 mi |
| Unalaska | May 6 | Oct 18 | 165 | 8a–8b | Dutch Harbor, AK |
| Valdez | Apr 30 | Oct 2 | 155 | 5a | Valdez Wso, AK, 3 mi |
| Nome | Jun 5 | Sep 3 | 90 | 3b | Nome Muni Airport, AK |
| Kotzebue | Jun 5 | Sep 24 | 111 | 2b | Kotzebue Ralph Wein Airport, AK, 4 mi |
| Seward | May 2 | Oct 7 | 158 | 5b | Seward Airport, AK |
| North Pole | May 22 | Sep 2 | 103 | 2a | N Pole 1N, AK |
| Cordova | Apr 24 | Oct 19 | 178 | 5a | Cordova N, AK, 4 mi |
Frost dates are the dates after (spring) or before (fall) which the chance of a 32°F freeze is below 50%, from NOAA’s 1991–2020 U.S. Climate Normals for the weather station nearest each city’s center. Zones are from the 2023 USDA Plant Hardiness Zone Map for the ZIP codes around each city; a range means nearby ZIP codes differ. Cities are the 20 largest by Census Bureau 2024 population estimates.
An average is not a guarantee. There’s still about a 1 in 2 chance of frost after the average last spring date. Many gardeners wait an extra week or two before setting out tomatoes, peppers and basil, and keep covers handy.
Planting dates for Anchorage
Timed from Anchorage’s average last frost of May 16, using University of New Hampshire Extension’s planting guidance. For your exact dates, enter your ZIP code in the calendar below.
| Crop | Start seeds indoors | Plant outside |
|---|---|---|
| Tomatoes | Mar 28 to Apr 11 | May 23 to May 30 |
| Peppers | Mar 21 to Apr 4 | May 30 |
| Lettuce | Mar 14 to Mar 21 | Apr 18 to Apr 25 |
| Broccoli | Mar 7 to Mar 21 | Apr 18 to May 2 |
| Cucumbers | Apr 25 to May 2 | May 23 to May 30 |
| Basil | Apr 4 to Apr 18 | May 30 |
When to plant, for your garden
Your seed-starting and planting dates, timed from your last spring frost. Full calendar, 12 crops.
Enter your ZIP code to look up your average last frost date and hardiness zone, or type the date in yourself.
Frost dates: NOAA U.S. Climate Normals, 1991–2020. Hardiness zones: USDA Plant Hardiness Zone Map, 2023, ZIP code data from PRISM Group, Oregon State University, prism.oregonstate.edu, accessed Oct. 20, 2026.
More about frost dates
How to find your last frost date, and what your zone means · Full planting calendar · How to start seeds indoors
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