Frost dates for Kotzebue Ralph Wein Airport, AK
At Kotzebue Ralph Wein Airport, the median last spring frost (32°F) is Jun 5 and the median first fall frost is Sep 24, for a typical growing season of 110 days. For a 90% chance that the last frost has passed, wait until Jun 17. Nearby ZIP codes are in USDA hardiness zones 1b to 2b.
- Jun 5Last spring frost (median)50% chance of 32°F after this date
- Jun 17Safer planting date10% chance of 32°F after this date
- Sep 24First fall frost (median)50% chance of 32°F by this date
- 110 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 | Jun 2 | Jun 15 | Jul 1 |
| 32°F | May 20 | Jun 5 | Jun 17 |
| 28°F | May 12 | May 27 | Jun 7 |
| 24°F | May 4 | May 16 | May 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 | Aug 24 | Sep 12 | Sep 25 |
| 32°F | Sep 7 | Sep 24 | Oct 6 |
| 28°F | Sep 20 | Oct 3 | Oct 15 |
| 24°F | Sep 28 | Oct 11 | Oct 21 |
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 | 61 days | 87 days | 107 days |
| 32°F | 87 days | 110 days | 128 days |
| 28°F | 110 days | 128 days | 147 days |
| 24°F | 128 days | 145 days | 162 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 99763 | 2b | -45 to -40°F | 70 km |
| 99752 | 2b | -45 to -40°F | 78 km |
| 99749 | 2a | -50 to -45°F | 97 km |
| 99770 | 2a | -50 to -45°F | 115 km |
| 99786 | 2a | -50 to -45°F | 207 km |
| 99773 | 1b | -55 to -50°F | 238 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 USW00026616, at 66.8667, -162.6333, elevation 9 m (30 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 236.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Deering Airport (89 km)
- Kivalina Airport (126 km)
- Nome Muni Airport (292 km)
- Kaltag Airport (334 km)
- Galena (353 km)
- Wainwright Airport (433 km)
- Ruby 44 ESE (469 km)
- Bettles Airport (485 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.