Frost dates for Glennallen 64 N, AK
At Glennallen 64 N, the median last spring frost (32°F) is Jun 5 and the median first fall frost is Aug 24, for a typical growing season of 76 days. For a 90% chance that the last frost has passed, wait until Jun 21. Nearby ZIP codes are in USDA hardiness zones 1b to 4b.
- Jun 5Last spring frost (median)50% chance of 32°F after this date
- Jun 21Safer planting date10% chance of 32°F after this date
- Aug 24First fall frost (median)50% chance of 32°F by this date
- 76 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 27 | Jun 5 | Jun 21 |
| 28°F | May 13 | May 23 | Jun 3 |
| 24°F | May 3 | May 11 | May 23 |
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 10 | Aug 24 | Sep 6 |
| 28°F | Aug 24 | Sep 8 | Sep 25 |
| 24°F | Sep 5 | Sep 25 | Oct 7 |
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 | 23 days | 41 days | 63 days |
| 32°F | 55 days | 76 days | 94 days |
| 28°F | 86 days | 107 days | 127 days |
| 24°F | 115 days | 135 days | 150 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 |
|---|---|---|---|
| 99737 | 3a | -40 to -35°F | 47 km |
| 99588 | 2b | -45 to -40°F | 71 km |
| 99586 | 2b | -45 to -40°F | 74 km |
| 99776 | 1b | -55 to -50°F | 106 km |
| 99706 | 3b | -35 to -30°F | 116 km |
| 99729 | 4a | -30 to -25°F | 127 km |
| 99714 | 3b | -35 to -30°F | 159 km |
| 99573 | 4b | -25 to -20°F | 163 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 USW00056401, at 63.0294, -145.5003, elevation 814 m (2,669 ft).
- Data quality: Estimated from nearby stations (2+ years), 7 years of freeze data.
- Average days per year at or below 32°F: 252.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Paxson (0 km)
- Dry Creek (85 km)
- Lake Susitna (88 km)
- Gulkana Airport (97 km)
- Gennallen Kcam (102 km)
- Delta Junction 20 SE (106 km)
- Big Delta Airport (108 km)
- Delta 5 NE (117 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.