Frost dates for Kaltag Airport, AK
At Kaltag Airport, the median last spring frost (32°F) is May 25 and the median first fall frost is Sep 3, for a typical growing season of 101 days. For a 90% chance that the last frost has passed, wait until Jun 11. Nearby ZIP codes are in USDA hardiness zones 2a to 3b.
- May 25Last spring frost (median)50% chance of 32°F after this date
- Jun 11Safer planting date10% chance of 32°F after this date
- Sep 3First fall frost (median)50% chance of 32°F by this date
- 101 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 |
|---|---|---|---|
| 32°F | May 10 | May 25 | Jun 11 |
| 28°F | May 2 | May 12 | May 29 |
| 24°F | Apr 25 | May 5 | May 19 |
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 |
|---|---|---|---|
| 32°F | Aug 18 | Sep 3 | Sep 21 |
| 28°F | Sep 1 | Sep 17 | Oct 2 |
| 24°F | Sep 10 | Sep 26 | Oct 11 |
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 | 45 days | 73 days | 94 days |
| 32°F | 74 days | 101 days | 122 days |
| 28°F | 104 days | 125 days | 146 days |
| 24°F | 125 days | 144 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 |
|---|---|---|---|
| 99748 | 2a | -50 to -45°F | 2 km |
| 99765 | 2a | -50 to -45°F | 54 km |
| 99684 | 3b | -35 to -30°F | 76 km |
| 99771 | 3b | -35 to -30°F | 118 km |
| 99753 | 3b | -35 to -30°F | 132 km |
| 99590 | 3a | -40 to -35°F | 173 km |
| 99665 | 3a | -40 to -35°F | 186 km |
| 99659 | 3b | -35 to -30°F | 192 km |
| 99558 | 3b | -35 to -30°F | 202 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 USW00026502, at 64.3267, -158.7417, elevation 55 m (181 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 234.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Galena (100 km)
- McGrath Airport (217 km)
- Ruby 44 ESE (222 km)
- Deering Airport (270 km)
- Minchumina (317 km)
- Nome Muni Airport (322 km)
- Farewell Lake (323 km)
- Tanana Calhoun Mem Airport (328 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.