Alaska frost dates: Last spring and first autumn frost at every NOAA station, 1991-2020
Across Alaska's 163 NOAA stations with frost dates, the median last spring frost (32°F) runs from April 4 in Annette Island Airport to June 12 in Cooper Landing; for half of its places it comes after May 18.
- Typical last spring frost
- May 18median of 72 places
- Typical first autumn frost
- September 23median of 72 places
- Earliest last frost
- April 4Annette Island Airport
- Latest last frost
- June 12Cooper Landing
When is the last frost in Alaska, town by town?
Each date is NOAA's: "after May 18 in half of years" means the last 32°F night of spring came after May 18 in half of the years 1991-2020. By the 1-in-10 date, the last frost has passed in nine years out of ten.
Find your town in the list, or look up a ZIP code for the stations nearest it.
| Place or station | Last frost (median) | 1 in 10 after | First frost (median) | 1 in 10 before | Growing season | Zone |
|---|---|---|---|---|---|---|
| Annette Island Airport | April 4 | April 22 | October 31 | October 15 | 208 days | 8a |
| Beaver Falls | April 4 | April 25 | November 9 | October 19 | 218 days | – |
| Juneau Lena Point | April 11 | April 27 | November 1 | October 13 | 202 days | 7b |
| WrangellWrangell Airport | April 11 | April 29 | November 1 | October 13 | 202 days | 7b |
| SitkaSitka Airport | April 12 | April 30 | November 1 | October 13 | 201 days | 8a |
| Craig | April 14 | May 2 | November 1 | October 16 | 201 days | – |
| Metlakatla6 mi S | April 14 | May 1 | October 25 | October 8 | 192 days | – |
| Port Alexander | April 18 | May 5 | November 5 | October 16 | 198 days | – |
| Point Baker | April 19 | May 5 | October 25 | October 5 | 187 days | – |
| Juneau Downtown | April 20 | May 5 | October 22 | October 5 | 183 days | – |
| Ketchikan (10 mi N) | April 20 | May 4 | October 26 | October 10 | 189 days | – |
| Little Port Walter | April 21 | May 9 | October 31 | October 5 | 190 days | 8a |
| SkagwaySkagway Airport | April 21 | May 2 | October 17 | October 1 | 176 days | 6b |
| KetchikanKetchikan International Airport | April 22 | May 9 | October 23 | October 3 | 185 days | 7b |
| Cordova N | April 24 | May 8 | October 19 | October 4 | 176 days | – |
| Palmer Job Corps | April 24 | May 9 | October 4 | September 22 | 164 days | 5a |
| HainesHaines Airport | April 25 | May 7 | October 12 | September 30 | 172 days | 6b |
| Whittier | April 25 | May 8 | October 14 | October 1 | 172 days | – |
| Elfin Cove | April 26 | May 8 | November 1 | October 15 | 188 days | 8a |
| Auke Bay | April 27 | May 11 | October 18 | September 30 | 172 days | 7a |
| Cordova Wastewater Treatment Plant | April 29 | May 13 | October 13 | September 25 | 169 days | – |
| Hidden Falls Hatchery | April 29 | May 15 | October 25 | October 7 | 176 days | – |
| Juneau Mile 17 | April 29 | May 10 | October 20 | October 2 | 173 days | – |
| KlawockKlawock Airport | April 29 | May 14 | October 16 | October 1 | 169 days | 8a |
| Kodiak Wastewater Treatment Plant | April 29 | May 13 | October 14 | September 30 | 168 days | – |
| PetersburgPetersburg 1 | April 29 | May 14 | October 17 | September 30 | 169 days | 7a |
| Haines #2 | April 30 | May 13 | October 7 | September 24 | 160 days | – |
| ValdezValdez Weather Office | April 30 | May 10 | October 2 | September 20 | 157 days | 6b |
| Anchorage Lake Hood Airport | May 1 | May 8 | October 3 | September 22 | 156 days | 5b |
| Anchorage Merrill Field | May 1 | May 9 | September 29 | September 17 | 150 days | 5b |
| Thorne Bay | May 1 | May 16 | October 13 | October 1 | 166 days | – |
| SewardSeward Airport | May 2 | May 17 | October 7 | September 28 | 158 days | 7a |
| Annex Creek | May 3 | May 18 | October 14 | October 1 | 164 days | – |
| Sitka (1 mi NE) | May 3 | May 19 | October 18 | October 1 | 166 days | 7b |
| Hyder | May 4 | May 23 | October 11 | October 1 | 157 days | – |
| JuneauJuneau Airport | May 4 | May 18 | October 3 | September 18 | 150 days | 6b |
| Pelican | May 4 | May 18 | October 19 | October 4 | 167 days | 7b |
| AnchorageAnchorage Ted Stevens International Airport | May 5 | May 15 | October 1 | September 18 | 147 days | 5b |
| Anchorage Forecast Office | May 5 | May 14 | September 29 | September 17 | 147 days | 5b |
| KodiakKodiak Airport | May 5 | May 21 | October 3 | September 22 | 151 days | 7a |
| Snettisham Power Plant | May 5 | May 22 | October 15 | September 30 | 162 days | – |
| Dutch Harbor | May 6 | May 22 | October 18 | September 20 | 164 days | 8a |
| Glacier Bay | May 6 | May 26 | October 10 | September 19 | 154 days | – |
| PalmerPalmer Municipal Airport | May 6 | May 18 | September 25 | September 11 | 140 days | 5a |
| Skagway station | May 6 | May 22 | October 1 | September 15 | 146 days | – |
| Anchorage Upper De Armoun | May 7 | May 23 | September 28 | September 16 | 143 days | – |
| Big River Lakes | May 7 | May 25 | October 7 | September 20 | 151 days | – |
| Alyeska | May 8 | May 22 | September 29 | September 14 | 142 days | 6a |
| Eagle River Gakona Circle | May 9 | May 22 | September 26 | September 12 | 139 days | 5b |
| Fort Richardson Water Treatment Plant | May 9 | May 22 | September 26 | September 9 | 138 days | 5a |
| Hoonah | May 9 | July 4 | October 4 | September 1 | 145 days | 7b |
| Juneau Forecast Office | May 9 | May 24 | October 4 | September 20 | 146 days | 6a |
| Ouzinkie | May 9 | May 23 | October 4 | September 22 | 148 days | – |
| HomerHomer Airport | May 10 | May 23 | September 29 | September 14 | 141 days | 6b |
| IliamnaIliamna Airport | May 10 | May 25 | October 1 | September 17 | 144 days | 5a |
| Port San Juan | May 10 | May 28 | October 7 | September 22 | 150 days | 7b |
| SeldoviaSeldovia Airport | May 10 | May 24 | October 1 | September 17 | 145 days | 7a |
| Kitoi Bay | May 11 | May 28 | October 6 | September 25 | 149 days | – |
| Sand Point1 mi ENE | May 11 | May 25 | October 18 | October 4 | 160 days | – |
| Anchorage Rabbit Creek #2 | May 12 | May 24 | September 26 | September 12 | 137 days | – |
| Ben's Farm | May 12 | May 24 | September 20 | September 6 | 129 days | 4a |
| Fairbanks (11 mi NE) | May 12 | May 29 | September 16 | August 29 | 124 days | – |
| Fort Knox Mine | May 12 | May 28 | September 17 | August 29 | 126 days | – |
| Port Alsworth station | May 12 | May 27 | September 24 | September 8 | 134 days | – |
| College (5 mi NW) | May 13 | May 31 | September 15 | August 29 | 122 days | – |
| FairbanksFairbanks International Airport | May 13 | May 26 | September 13 | August 29 | 121 days | 2a |
| Fairbanks Midtown | May 13 | May 28 | September 10 | August 28 | 119 days | – |
| McGrathMcGrath Airport | May 13 | May 28 | September 13 | August 27 | 120 days | 2a |
| Minchumina | May 13 | May 28 | September 17 | September 3 | 124 days | – |
| Yakutat (3 mi SSE) | May 13 | May 29 | September 26 | September 13 | 133 days | – |
| Matanuska Experiment Farm | May 14 | May 26 | September 20 | September 6 | 127 days | 4b |
| Valdez station | May 14 | May 26 | September 22 | September 6 | 129 days | – |
| Keystone Ridge | May 15 | May 31 | September 16 | August 30 | 122 days | 3b |
| NenanaNenana Municipal Airport | May 15 | May 29 | September 11 | August 27 | 117 days | 2a |
| WillowWillow West | May 15 | May 28 | September 18 | September 4 | 126 days | – |
| Aurora | May 16 | May 29 | September 6 | August 25 | 112 days | 2b |
| Cannery Creek | May 16 | May 29 | October 3 | September 21 | 139 days | 6b |
| Eagle River Nature Center | May 16 | June 9 | September 20 | September 4 | 125 days | – |
| Fairbanks Airport #2 | May 16 | May 30 | September 8 | August 27 | 113 days | – |
| Homer (8 mi NW) | May 16 | May 30 | September 30 | September 16 | 136 days | – |
| North LakesAnderson Lake | May 16 | May 31 | September 23 | September 8 | 128 days | – |
| TalkeetnaTalkeetna Airport | May 16 | May 28 | September 16 | September 1 | 122 days | 4a |
| University Experiment Station | May 16 | May 30 | September 8 | August 26 | 114 days | 2b |
| Delta JunctionBig Delta Airport | May 17 | May 31 | September 7 | August 23 | 113 days | 2b |
| BadgerNorth Pole | May 18 | May 31 | September 5 | August 24 | 110 days | 1b |
| CollegeCollege Obsy | May 18 | June 1 | September 6 | August 24 | 111 days | 2b |
| Cooper Lake Project | May 18 | May 31 | September 27 | September 12 | 130 days | – |
| Eklutna Water Treatment Plant | May 18 | May 30 | September 20 | September 4 | 124 days | 5a |
| Galena | May 18 | June 1 | September 8 | August 24 | 111 days | 1b |
| Glen Alps | May 18 | May 31 | September 23 | September 8 | 125 days | 5b |
| Hope | May 18 | May 28 | September 24 | September 12 | 127 days | – |
| Kenai (9 mi N) | May 18 | May 30 | September 22 | September 6 | 125 days | – |
| Little Su At Hatcher Pass Bridge | May 18 | May 30 | September 18 | September 2 | 122 days | – |
| Main Bay | May 19 | June 4 | October 6 | September 24 | 139 days | 6b |
| Eielson Field | May 20 | June 3 | September 1 | August 20 | 104 days | – |
| Sterling6 mi SW | May 20 | June 1 | September 21 | September 6 | 123 days | – |
| Wally Noerenberg Hatchery | May 20 | June 1 | October 9 | September 26 | 142 days | – |
| YakutatYakutat Airport | May 20 | May 31 | September 23 | September 5 | 124 days | 6b |
| BethelBethel Airport | May 21 | June 2 | September 22 | September 7 | 122 days | 4a |
| Eagle River (5 mi SE) | May 21 | June 3 | September 15 | August 31 | 116 days | 4b |
| Eaglecrest Base | May 21 | June 2 | October 1 | September 19 | 132 days | – |
| Seward (19 mi N) | May 21 | May 31 | September 26 | September 13 | 127 days | – |
| BettlesBettles Airport | May 22 | June 5 | August 24 | August 10 | 94 days | 1b |
| Lazy Mountain | May 22 | June 3 | September 16 | September 1 | 114 days | 5a |
| North Pole1 mi N | May 22 | June 4 | September 2 | August 20 | 102 days | – |
| Ruby (44 mi ESE) | May 22 | June 3 | September 3 | August 21 | 101 days | – |
| CordovaCordova M K Smith Airport | May 23 | June 5 | September 19 | September 5 | 118 days | 6a |
| Skwentna | May 23 | June 4 | September 9 | August 26 | 109 days | – |
| Clear Sky | May 24 | June 12 | September 4 | August 19 | 100 days | – |
| Ester | May 24 | June 4 | September 1 | August 19 | 98 days | – |
| Haines (40 mi NW) | May 24 | June 10 | September 20 | September 1 | 118 days | – |
| KenaiKenai Municipal Airport | May 24 | June 4 | September 12 | August 29 | 110 days | 4a |
| Kobe Hill | May 24 | June 10 | September 2 | August 17 | 100 days | – |
| CentralCentral #2 | May 25 | June 6 | August 26 | August 12 | 92 days | – |
| Cold BayCold Bay Airport | May 25 | June 10 | October 4 | September 20 | 131 days | 7a |
| Denali (27 mi N) | May 25 | June 3 | September 8 | August 26 | 105 days | – |
| KaltagKaltag Airport | May 25 | June 11 | September 3 | August 18 | 101 days | 2a |
| King SalmonKing Salmon Airport | May 26 | June 11 | September 15 | August 31 | 111 days | 4a |
| NorthwayNorthway Airport | May 26 | June 8 | September 1 | August 18 | 97 days | 1b |
| WhitestoneWhitestone Farms | May 26 | June 9 | September 2 | August 19 | 98 days | – |
| Healy | May 27 | June 10 | September 1 | August 18 | 97 days | – |
| Homer (9 mi E) | May 27 | June 8 | September 22 | September 4 | 116 days | – |
| Monashka Creek Dam | May 27 | June 10 | September 23 | September 5 | 117 days | – |
| Portage Glacier V C | May 27 | June 11 | September 12 | August 24 | 106 days | 5a |
| Amber Lake | May 28 | June 9 | September 13 | August 30 | 107 days | – |
| Campbell Creek Science Center | May 28 | June 6 | September 12 | August 30 | 107 days | – |
| Fox2 mi SE | May 28 | June 9 | September 1 | August 17 | 96 days | – |
| Gustavus2 mi NE | May 28 | June 12 | September 25 | August 29 | 116 days | – |
| Mile 42 Steese | May 28 | June 19 | August 26 | August 9 | 87 days | – |
| Port Alcan | May 28 | June 10 | August 29 | August 14 | 91 days | 2a |
| Eagle station | May 29 | June 11 | August 23 | August 8 | 86 days | – |
| TananaTanana Calhoun Mem Airport | May 29 | June 16 | August 28 | August 10 | 89 days | 1b |
| Whites Crossing | May 29 | June 9 | September 7 | August 24 | 100 days | – |
| Dry Creek | May 30 | June 13 | August 24 | August 9 | 84 days | 2a |
| Farewell Lake | May 30 | June 15 | September 5 | August 22 | 97 days | – |
| Gustavus station | May 30 | June 22 | September 16 | August 29 | 107 days | – |
| Lake Susitna | May 30 | June 9 | September 4 | August 17 | 95 days | – |
| Two Rivers | May 30 | June 13 | September 2 | August 13 | 95 days | – |
| Moose Pass3 mi NW | May 31 | June 15 | September 8 | August 24 | 99 days | – |
| Silver Lake | May 31 | June 10 | September 3 | August 20 | 95 days | – |
| St. GeorgeSt George Island Airport | May 31 | June 23 | October 5 | September 17 | 128 days | 7a |
| Gilmore Creek | June 1 | June 17 | August 28 | August 13 | 87 days | 2b |
| Kenai (29 mi ENE) | June 1 | June 18 | September 8 | August 21 | 94 days | – |
| Sutton (1 mi W) | June 1 | June 13 | September 6 | August 24 | 98 days | 4a |
| Hayes River | June 2 | June 11 | September 8 | August 23 | 98 days | – |
| Port Alsworth1 mi SW | June 2 | June 13 | September 12 | August 29 | 101 days | – |
| Tok #2 | June 3 | July 13 | August 27 | August 11 | 79 days | – |
| Delta (5 mi NE) | June 4 | July 17 | August 22 | August 7 | 75 days | – |
| Intricate Bay | June 4 | June 22 | September 12 | August 28 | 98 days | – |
| Nabesna | June 4 | July 3 | September 1 | August 19 | 85 days | – |
| St. PaulSaint Paul Island Airport | June 4 | June 25 | September 28 | September 11 | 114 days | 6b |
| Delta Junction (20 mi SE) | June 5 | June 30 | August 21 | August 8 | 75 days | 1b |
| Glennallen (64 mi N) | June 5 | June 21 | August 24 | August 10 | 76 days | – |
| KotzebueKotzebue Airport | June 5 | June 17 | September 24 | September 7 | 110 days | 3a |
| NomeNome Airport | June 5 | June 26 | September 3 | August 15 | 88 days | 3b |
| St. Paul (4 mi NE) | June 5 | July 1 | September 28 | September 3 | 110 days | – |
| McKinley Park | June 6 | June 30 | August 25 | August 9 | 77 days | 3a |
| GulkanaGulkana Airport | June 7 | July 5 | August 21 | August 8 | 73 days | 2b |
| Puntilla | June 7 | June 30 | September 2 | August 14 | 83 days | – |
| King Salmon (42 mi SE) | June 9 | June 22 | September 11 | August 26 | 93 days | – |
| KivalinaKivalina Airport | June 10 | June 23 | September 11 | August 26 | 92 days | – |
| Soldotna5 mi SSW | June 11 | July 7 | September 1 | August 11 | 75 days | – |
| Cooper Landing5 mi W | June 12 | July 2 | September 1 | August 14 | 78 days | – |
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities, growing-season length); station daily lows via ACIS (zone). Growing season: NOAA's median number of days between the last spring and first autumn 32°F night. Zone: the USDA's plant hardiness rule applied to the station's own 1991-2020 coldest nights.