Home › Frost dates › Alaska
Alaska frost dates
Across the 55Alaska weather stations below, the average last spring frost ranges from Apr 4 in Annette Island to Jun 10 in Kivalina. The statewide middle is about May 17 for the last spring frost and Sep 24 for the first fall frost. Annette Island has the longest growing season, about 210 days. Hardiness zones in these places: 1b, 2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a.
Frost dates by city
| Place | Zone | Last spring frost | 90% safe after | First fall frost | Frost-free days |
|---|---|---|---|---|---|
| Annette Island | 8a | Apr 4 | Apr 22 | Oct 31 | 210 |
| Sitka | 7b | Apr 12 | Apr 30 | Nov 1 | 203 |
| Metlakatla 6 S | 8a | Apr 14 | May 1 | Oct 25 | 194 |
| Skagway | 5a | Apr 21 | May 2 | Oct 17 | 179 |
| Ketchikan | 8a | Apr 22 | May 9 | Oct 23 | 184 |
| Haines | 5a | Apr 25 | May 7 | Oct 12 | 170 |
| Klawock | 7b | Apr 29 | May 14 | Oct 16 | 170 |
| Petersburg 1 | 7b | Apr 29 | May 14 | Oct 17 | 171 |
| Valdez | 5a | Apr 30 | May 10 | Oct 2 | 155 |
| Anchorage Lake Hood | 5b | May 1 | May 8 | Oct 3 | 155 |
| Anchorage Merrill | 5a | May 1 | May 9 | Sep 29 | 151 |
| Seward | 5b | May 2 | May 17 | Oct 7 | 158 |
| Sitka 1 Ne | 7b | May 3 | May 19 | Oct 18 | 168 |
| Juneau | 7a | May 4 | May 18 | Oct 3 | 152 |
| Anchorage | 5b | May 5 | May 15 | Oct 1 | 149 |
| Kodiak | 7b | May 5 | May 21 | Oct 3 | 151 |
| Palmer | 5a | May 6 | May 18 | Sep 25 | 142 |
| Homer | 6a | May 10 | May 23 | Sep 29 | 142 |
| Iliamna | 4b | May 10 | May 25 | Oct 1 | 144 |
| Seldovia | 6b | May 10 | May 24 | Oct 1 | 144 |
| Sand Point 1 Ene | 7b | May 11 | May 25 | Oct 18 | 160 |
| Fairbanks 11 Ne | 2a | May 12 | May 29 | Sep 16 | 127 |
| Fairbanks | 2b | May 13 | May 26 | Sep 13 | 123 |
| Mcgrath | 2a | May 13 | May 28 | Sep 13 | 123 |
| Yakutat 3 Sse | 6b | May 13 | May 29 | Sep 26 | 136 |
| Nenana | 2a | May 15 | May 29 | Sep 11 | 119 |
| Talkeetna | 4b | May 16 | May 28 | Sep 16 | 123 |
| Big Delta | 3b | May 17 | May 31 | Sep 7 | 113 |
| Yakutat | 6b | May 20 | May 31 | Sep 23 | 126 |
| Bethel | 4a | May 21 | Jun 2 | Sep 22 | 124 |
| Bettles | 1b | May 22 | Jun 5 | Aug 24 | 94 |
| Ruby 44 Ese | 3a | May 22 | Jun 3 | Sep 3 | 104 |
| Cordova M K Smith | 5a | May 23 | Jun 5 | Sep 19 | 119 |
| Skwentna | 4b | May 23 | Jun 4 | Sep 9 | 109 |
| Kenai | 4b | May 24 | Jun 4 | Sep 12 | 111 |
| Cold Bay | 7a | May 25 | Jun 10 | Oct 4 | 132 |
| Denali 27 N | 2a | May 25 | Jun 3 | Sep 8 | 106 |
| Kaltag | 2a | May 25 | Jun 11 | Sep 3 | 101 |
| King Salmon | 4b | May 26 | Jun 11 | Sep 15 | 112 |
| Northway | 2a | May 26 | Jun 8 | Sep 1 | 98 |
| Portage Glacier V C | 5b | May 27 | Jun 11 | Sep 12 | 108 |
| Gustavus 2 Ne | 7a | May 28 | Jun 12 | Sep 25 | 120 |
| Tanana Calhoun | 1b | May 29 | Jun 16 | Aug 28 | 91 |
| Gustavus | 7a | May 30 | Jun 22 | Sep 16 | 109 |
| George Island | 7a | May 31 | Jun 23 | Oct 5 | 127 |
| Kenai 29 Ene | 5a | Jun 1 | Jun 18 | Sep 8 | 99 |
| Port Alsworth 1 Sw | 4a | Jun 2 | Jun 13 | Sep 12 | 102 |
| Paul Island | 6b | Jun 4 | Jun 25 | Sep 28 | 116 |
| . Paul 4 Ne | 6b | Jun 5 | Jul 1 | Sep 28 | 115 |
| Glennallen 64 N | 3a | Jun 5 | Jun 21 | Aug 24 | 80 |
| Kotzebue Ralph Wein | 2b | Jun 5 | Jun 17 | Sep 24 | 111 |
| Nome | 3b | Jun 5 | Jun 26 | Sep 3 | 90 |
| Gulkana | 4b | Jun 7 | Jul 5 | Aug 21 | 75 |
| King Salmon 42 Se | 4b | Jun 9 | Jun 22 | Sep 11 | 94 |
| Kivalina | 3a | Jun 10 | Jun 23 | Sep 11 | 93 |
Dates are the 50% probability of a 32°F freeze (NOAA 1991–2020 normals); "90% safe after" is the date after which a later spring freeze happens in only 1 year in 10.
When to plant in Alaska
Using the statewide middle dates (last frost May 17, first frost Sep 24). Adjust for your town with the table above or the planting calendar.
| Plant | When to plant in Alaska |
|---|---|
| Tomatoes | May 24 – Jun 7 |
| Peas | Apr 5 – Apr 26; fall: Jul 2 – Jul 23 |
| Potatoes | Apr 19 – May 10 |
| Green beans | May 24 – Jun 7; fall: Jul 9 – Jul 23 |
| Garlic | Sep 24 – Oct 22 |
| Tulips | Sep 10 – Oct 22 |