Last spring frost
May 29
Frost Dates for Big Lake, AK
First fall frost
Sep 7
Growing season
100 days
In an average year around Big Lake, AK, the last spring frost (32°F) is about May 29 and the first fall frost is about Sep 7, giving roughly a 100-day growing season. To be safe most years, wait until May 13 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 9 | May 29 | May 13 |
| Hard (28°F) | May 27 | May 14 | Apr 29 |
| Severe (24°F) | May 17 | May 1 | Apr 18 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 32°F | Jun 9 | Jun 5 | Jun 2 | May 31 | May 29 | May 26 | May 24 | May 20 | May 13 |
| 28°F | May 27 | May 24 | May 21 | May 17 | May 14 | May 10 | May 6 | May 3 | Apr 29 |
| 24°F | May 17 | May 11 | May 7 | May 4 | May 1 | Apr 29 | Apr 27 | Apr 23 | Apr 18 |
| 20°F | May 4 | Apr 30 | Apr 28 | Apr 24 | Apr 20 | Apr 17 | Apr 14 | Apr 12 | Apr 8 |
| 16°F | Apr 27 | Apr 21 | Apr 17 | Apr 13 | Apr 11 | Apr 9 | Apr 6 | Apr 4 | Apr 2 |
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) | Aug 24 | Sep 7 | Sep 21 |
| Hard (28°F) | Sep 3 | Sep 19 | Oct 2 |
| Severe (24°F) | Sep 13 | Sep 29 | Oct 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 32°F | Aug 24 | Aug 29 | Sep 1 | Sep 4 | Sep 7 | Sep 10 | Sep 14 | Sep 17 | Sep 21 |
| 28°F | Sep 3 | Sep 7 | Sep 12 | Sep 16 | Sep 19 | Sep 21 | Sep 24 | Sep 27 | Oct 2 |
| 24°F | Sep 13 | Sep 19 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 4 | Oct 8 | Oct 15 |
| 20°F | Sep 24 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 11 | Oct 15 | Oct 18 | Oct 24 |
| 16°F | Oct 1 | Oct 5 | Oct 9 | Oct 12 | Oct 16 | Oct 18 | Oct 22 | Oct 26 | Nov 1 |
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: Whites Crossing, Ak, about 13.2 miles away@if(!empty($station['elevation_ft'])), at 270 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 Big Lake, AK?
On average, the last spring frost (32°F) around Big Lake, AK is about May 29. In cooler years it can run later, so for a safer bet many gardeners wait until May 13.
When is the first frost in the fall?
The first fall frost around Big Lake, AK typically arrives about Sep 7. 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 29 on average, or May 13 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 100 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 99652 Planting calendar → Alaska frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026