Last spring frost
May 31
Frost Dates for St. George, AK
First fall frost
Oct 5
Growing season
128 days
In an average year around St. George, AK, the last spring frost (32°F) is about May 31 and the first fall frost is about Oct 5, giving roughly a 128-day growing season. To be safe most years, wait until May 10 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Freeze (32°F) | Jun 23 | May 31 | May 10 |
| Hard (28°F) | May 29 | May 9 | Apr 24 |
| Severe (24°F) | May 11 | Apr 25 | Apr 6 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 32°F | Jun 23 | Jun 14 | Jun 7 | Jun 3 | May 31 | May 28 | May 24 | May 17 | May 10 |
| 28°F | May 29 | May 23 | May 17 | May 12 | May 9 | May 5 | May 2 | Apr 29 | Apr 24 |
| 24°F | May 11 | May 5 | May 1 | Apr 28 | Apr 25 | Apr 22 | Apr 18 | Apr 14 | Apr 6 |
| 20°F | Apr 29 | Apr 24 | Apr 20 | Apr 16 | Apr 12 | Apr 8 | Apr 4 | Apr 1 | Mar 24 |
| 16°F | Apr 18 | Apr 12 | Apr 7 | Apr 5 | Apr 2 | Mar 30 | Mar 24 | Mar 17 | Feb 28 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Freeze (32°F) | Sep 17 | Oct 5 | Oct 21 |
| Hard (28°F) | Oct 5 | Oct 24 | Nov 12 |
| Severe (24°F) | Oct 24 | Nov 13 | Dec 4 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 32°F | Sep 17 | Sep 24 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 12 | Oct 16 | Oct 21 |
| 28°F | Oct 5 | Oct 12 | Oct 17 | Oct 20 | Oct 24 | Oct 28 | Nov 1 | Nov 5 | Nov 12 |
| 24°F | Oct 24 | Oct 30 | Nov 3 | Nov 8 | Nov 13 | Nov 17 | Nov 22 | Nov 27 | Dec 4 |
| 20°F | Nov 5 | Nov 15 | Nov 22 | Nov 26 | Nov 30 | Dec 4 | Dec 8 | Dec 14 | Dec 21 |
| 16°F | Nov 28 | Dec 3 | Dec 9 | Dec 13 | Dec 18 | Dec 22 | Dec 27 | Jan 1 | Jan 16 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: St George Island Ap, Ak, about 4.4 miles away@if(!empty($station['elevation_ft'])), at 125 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in St. George, AK?
On average, the last spring frost (32°F) around St. George, AK is about May 31. In cooler years it can run later, so for a safer bet many gardeners wait until May 10.
When is the first frost in the fall?
The first fall frost around St. George, AK typically arrives about Oct 5. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around May 31 on average, or May 10 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 128 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 99591 Planting calendar → Alaska frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026