Frost dates for Bettles Airport, AK
At Bettles Airport, the median last spring frost (32°F) is May 22 and the median first fall frost is Aug 24, for a typical growing season of 94 days. For a 90% chance that the last frost has passed, wait until Jun 5. Nearby ZIP codes are in USDA hardiness zones 1a to 1b.
- May 22Last spring frost (median)50% chance of 32°F after this date
- Jun 5Safer planting date10% chance of 32°F after this date
- Aug 24First fall frost (median)50% chance of 32°F by this date
- 94 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 11 | May 22 | Jun 5 |
| 28°F | May 4 | May 13 | May 28 |
| 24°F | Apr 29 | May 7 | May 22 |
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 9 |
| 28°F | Aug 22 | Sep 5 | Sep 25 |
| 24°F | Sep 1 | Sep 19 | Oct 4 |
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 | 43 days | 67 days | 86 days |
| 32°F | 74 days | 94 days | 111 days |
| 28°F | 96 days | 115 days | 136 days |
| 24°F | 112 days | 133 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% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 99726 | 1b | -55 to -50°F | 18 km |
| 99720 | 1a | -60 to -55°F | 68 km |
| 99751 | 1b | -55 to -50°F | 236 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 USW00026533, at 66.9161, -151.5089, elevation 196 m (642 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 239.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Wiseman (82 km)
- Chandalar Lake (146 km)
- Chandalar Shelf Dot (153 km)
- Tanana Calhoun Mem Airport (196 km)
- Manley Hot Springs 15ne (208 km)
- Toolik Lake 5 ENE (212 km)
- Keystone Ridge (267 km)
- Mile 42 Steese (272 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.