Alaska frost dates
The typical last spring frost ranges from Apr 12 in Sitka to Jun 6 in Denali Park.
8 of the 8 Alaska cities listed have typical frost dates. The longest frost-free season is 201 days in Sitka; the shortest is 77 days in Denali Park. For a single address, look up your ZIP code: rural ZIPs use their nearest suitable station.
| City | Last spring frost | 1 in 10 after | First fall frost | 1 in 10 before | Hard freeze (28°F) | Season |
|---|---|---|---|---|---|---|
| Anchorage | May 5 | May 15 | Oct 1 | Sep 18 | Apr 22 / Oct 10 | 147 days |
| Denali Park | Jun 6 | Jun 30 | Aug 25 | Aug 9 | May 21 / Sep 6 | 77 days |
| Fairbanks | May 13 | May 26 | Sep 13 | Aug 29 | May 4 / Sep 23 | 121 days |
| Juneau | May 4 | May 18 | Oct 3 | Sep 18 | Apr 19 / Oct 18 | 150 days |
| Ketchikan | Apr 22 | May 9 | Oct 23 | Oct 3 | Mar 31 / Nov 10 | 185 days |
| Seward | May 2 | May 17 | Oct 7 | Sep 28 | Apr 15 / Oct 21 | 158 days |
| Sitka | Apr 12 | Apr 30 | Nov 1 | Oct 13 | Mar 24 / Nov 22 | 201 days |
| Skagway | Apr 21 | May 2 | Oct 17 | Oct 1 | Apr 5 / Nov 2 | 176 days |
Reading the table: Juneau
In Juneau, the last spring frost typically comes around May 4: in half of years it is earlier, in half later. In 1 year in 10 it comes after May 18, 14 days later, so tender plants set out after that date have a 90% chance of escaping frost. In fall, the first frost typically arrives around Oct 3, and in 1 year in 10 before Sep 18. Hard freezes (28°F) usually end earlier in spring and start later in fall: around Apr 19 and Oct 18 in Juneau.
Frost dates at more Alaska weather stations
NOAA stations across Alaska used by our ZIP code lookup, named for the town they are in.
| Station | Elevation | Last spring frost | First fall frost |
|---|---|---|---|
| Anchorage Upper De Armoun | 1,335 ft | May 7 (1 in 10 after May 23) | Sep 28 (before Sep 16) |
| Annette Island Airport | 109 ft | Apr 4 (1 in 10 after Apr 22) | Oct 31 (before Oct 15) |
| Bethel Airport | 102 ft | May 21 (1 in 10 after Jun 2) | Sep 22 (before Sep 7) |
| Bettles Airport | 642 ft | May 22 (1 in 10 after Jun 5) | Aug 24 (before Aug 10) |
| Cannery Creek | 85 ft | May 16 (1 in 10 after May 29) | Oct 3 (before Sep 21) |
| Central #2 | 920 ft | May 25 (1 in 10 after Jun 6) | Aug 26 (before Aug 12) |
| Clear Sky | 646 ft | May 24 (1 in 10 after Jun 12) | Sep 4 (before Aug 19) |
| Cold Bay Airport | 78 ft | May 25 (1 in 10 after Jun 10) | Oct 4 (before Sep 20) |
| College 5 Nw | 978 ft | May 13 (1 in 10 after May 31) | Sep 15 (before Aug 29) |
| College Obsy | 597 ft | May 18 (1 in 10 after Jun 1) | Sep 6 (before Aug 24) |
| Craig | 43 ft | Apr 14 (1 in 10 after May 2) | Nov 1 (before Oct 16) |
| Delta Junction 20 Se | 1,125 ft | Jun 5 (1 in 10 after Jun 30) | Aug 21 (before Aug 8) |
| Dutch Harbor | 10 ft | May 6 (1 in 10 after May 22) | Oct 18 (before Sep 20) |
| Eielson Fld | 547 ft | May 20 (1 in 10 after Jun 3) | Sep 1 (before Aug 20) |
| Elfin Cove | 20 ft | Apr 26 (1 in 10 after May 8) | Nov 1 (before Oct 15) |
| Farewell Lake | 1,060 ft | May 30 (1 in 10 after Jun 15) | Sep 5 (before Aug 22) |
| Galena | 152 ft | May 18 (1 in 10 after Jun 1) | Sep 8 (before Aug 24) |
| Gustavus | 40 ft | May 30 (1 in 10 after Jun 22) | Sep 16 (before Aug 29) |
| Hidden Falls Hatchery | 22 ft | Apr 29 (1 in 10 after May 15) | Oct 25 (before Oct 7) |
| Homer 8 Nw | 1,080 ft | May 16 (1 in 10 after May 30) | Sep 30 (before Sep 16) |
| Homer Airport | 64 ft | May 10 (1 in 10 after May 23) | Sep 29 (before Sep 14) |
| Hoonah | 130 ft | May 9 (1 in 10 after Jul 4) | Oct 4 (before Sep 1) |
| Iliamna Airport | 143 ft | May 10 (1 in 10 after May 25) | Oct 1 (before Sep 17) |
| Kaltag Airport | 181 ft | May 25 (1 in 10 after Jun 11) | Sep 3 (before Aug 18) |
| Kenai 29 Ene | 282 ft | Jun 1 (1 in 10 after Jun 18) | Sep 8 (before Aug 21) |
| Kenai Muni Airport | 91 ft | May 24 (1 in 10 after Jun 4) | Sep 12 (before Aug 29) |
| King Salmon | 63 ft | May 26 (1 in 10 after Jun 11) | Sep 15 (before Aug 31) |
| Kivalina Airport | 10 ft | Jun 10 (1 in 10 after Jun 23) | Sep 11 (before Aug 26) |
| Klawock Airport | 12 ft | Apr 29 (1 in 10 after May 14) | Oct 16 (before Oct 1) |
| Kobe Hill | 800 ft | May 24 (1 in 10 after Jun 10) | Sep 2 (before Aug 17) |
| Kodiak Airport | 80 ft | May 5 (1 in 10 after May 21) | Oct 3 (before Sep 22) |
| Lake Susitna | 2,375 ft | May 30 (1 in 10 after Jun 9) | Sep 4 (before Aug 17) |
| Lazy Mtn | 733 ft | May 22 (1 in 10 after Jun 3) | Sep 16 (before Sep 1) |
| Matanuska Exp Farm | 172 ft | May 14 (1 in 10 after May 26) | Sep 20 (before Sep 6) |
| Mcgrath Airport | 333 ft | May 13 (1 in 10 after May 28) | Sep 13 (before Aug 27) |
| Minchumina | 1,025 ft | May 13 (1 in 10 after May 28) | Sep 17 (before Sep 3) |
| N Pole | 475 ft | May 18 (1 in 10 after May 31) | Sep 5 (before Aug 24) |
| Nenana Muni Airport | 360 ft | May 15 (1 in 10 after May 29) | Sep 11 (before Aug 27) |
| Northway Airport | 1,713 ft | May 26 (1 in 10 after Jun 8) | Sep 1 (before Aug 18) |
| Petersburg 1 | 107 ft | Apr 29 (1 in 10 after May 14) | Oct 17 (before Sep 30) |
| Port Alexander | 12 ft | Apr 18 (1 in 10 after May 5) | Nov 5 (before Oct 16) |
| Port Alsworth | 260 ft | May 12 (1 in 10 after May 27) | Sep 24 (before Sep 8) |
| Pt Baker | 20 ft | Apr 19 (1 in 10 after May 5) | Oct 25 (before Oct 5) |
| Sand Point 1 Ene | 240 ft | May 11 (1 in 10 after May 25) | Oct 18 (before Oct 4) |
| Soldotna 5SSW | 180 ft | Jun 11 (1 in 10 after Jul 7) | Sep 1 (before Aug 11) |
| St George Island Airport | 125 ft | May 31 (1 in 10 after Jun 23) | Oct 5 (before Sep 17) |
| St Paul Island Airport | 35 ft | Jun 4 (1 in 10 after Jun 25) | Sep 28 (before Sep 11) |
| Talkeetna Airport | 350 ft | May 16 (1 in 10 after May 28) | Sep 16 (before Sep 1) |
| Tanana Calhoun Mem Airport | 227 ft | May 29 (1 in 10 after Jun 16) | Aug 28 (before Aug 10) |
| Thorne Bay | 286 ft | May 1 (1 in 10 after May 16) | Oct 13 (before Oct 1) |
| Valdez WSO | 95 ft | Apr 30 (1 in 10 after May 10) | Oct 2 (before Sep 20) |
| Wally Noerenberg Hatchery | 35 ft | May 20 (1 in 10 after Jun 1) | Oct 9 (before Sep 26) |
| Whites Crossing | 270 ft | May 29 (1 in 10 after Jun 9) | Sep 7 (before Aug 24) |
| Wrangell Airport | 56 ft | Apr 11 (1 in 10 after Apr 29) | Nov 1 (before Oct 13) |
| Yakutat State Airport | 33 ft | May 20 (1 in 10 after May 31) | Sep 23 (before Sep 5) |
32°F dates from NOAA 1991-2020 freeze probabilities for each city's station. "1 in 10 after": a 10% chance of a later spring frost (planting is 90% safe after it). How to read frost dates.