Frost dates for Little Port Walter, AK
At Little Port Walter, the median last spring frost (32°F) is Apr 21 and the median first fall frost is Oct 31, for a typical growing season of 190 days. For a 90% chance that the last frost has passed, wait until May 9. Nearby ZIP codes are in USDA hardiness zones 7a to 8a.
- Apr 21Last spring frost (median)50% chance of 32°F after this date
- May 9Safer planting date10% chance of 32°F after this date
- Oct 31First fall frost (median)50% chance of 32°F by this date
- 190 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Apr 29 | May 13 | May 29 |
| 32°F | Mar 31 | Apr 21 | May 9 |
| 28°F | Mar 6 | Mar 27 | Apr 13 |
| 24°F | Jan 27 | Mar 5 | Mar 30 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 25 | Oct 14 | Oct 30 |
| 32°F | Oct 5 | Oct 31 | Nov 20 |
| 28°F | Oct 31 | Nov 22 | Dec 18 |
| 24°F | Nov 17 | Dec 11 | Jan 18 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 123 days | 151 days | 174 days |
| 32°F | 160 days | 190 days | 218 days |
| 28°F | 210 days | 240 days | 272 days |
| 24°F | 246 days | 285 days | 328 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 99836 | 8a | 10 to 15°F | 15 km |
| 99830 | 7b | 5 to 10°F | 55 km |
| 99927 | 8a | 10 to 15°F | 65 km |
| 99835 | 7b | 5 to 10°F | 68 km |
| 99833 | 7b | 5 to 10°F | 103 km |
| 99820 | 7a | 0 to 5°F | 113 km |
| 99918 | 8a | 10 to 15°F | 132 km |
| 99925 | 7b | 5 to 10°F | 141 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00505519, at 56.3831, -134.6497, elevation 4 m (14 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 105.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Port Alexander (15 km)
- Point Baker (63 km)
- Sitka 1 NE (86 km)
- Sitka Airport (86 km)
- Hidden Falls Hatchery (94 km)
- Petersburg 1 (115 km)
- Klawock Airport (133 km)
- Craig (138 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.