Frost dates for Healy, AK
At Healy, the median last spring frost (32°F) is May 27 and the median first fall frost is Sep 1, for a typical growing season of 97 days. For a 90% chance that the last frost has passed, wait until Jun 10. Nearby ZIP codes are in USDA hardiness zones 2a to 4a.
- May 27Last spring frost (median)50% chance of 32°F after this date
- Jun 10Safer planting date10% chance of 32°F after this date
- Sep 1First fall frost (median)50% chance of 32°F by this date
- 97 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 | May 27 | Jun 8 | Jun 27 |
| 32°F | May 11 | May 27 | Jun 10 |
| 28°F | Apr 30 | May 12 | May 30 |
| 24°F | Apr 19 | May 3 | 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 |
|---|---|---|---|
| 36°F | Aug 8 | Aug 22 | Sep 6 |
| 32°F | Aug 18 | Sep 1 | Sep 19 |
| 28°F | Aug 27 | Sep 13 | Sep 29 |
| 24°F | Sep 9 | Sep 23 | 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 | 47 days | 73 days | 93 days |
| 32°F | 76 days | 97 days | 120 days |
| 28°F | 97 days | 121 days | 144 days |
| 24°F | 119 days | 142 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% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 99755 | 3b | -35 to -30°F | 16 km |
| 99704 | 2a | -50 to -45°F | 48 km |
| 99743 | 2a | -50 to -45°F | 49 km |
| 99744 | 2a | -50 to -45°F | 52 km |
| 99760 | 2a | -50 to -45°F | 62 km |
| 99729 | 4a | -30 to -25°F | 86 km |
| 99709 | 3b | -35 to -30°F | 119 km |
| 99725 | 3b | -35 to -30°F | 120 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 USC00503585, at 63.8675, -148.9942, elevation 432 m (1,417 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 218.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- McKinley Park (17 km)
- Kobe Hill (42 km)
- Clear Sky (43 km)
- Cantwell 2 E (53 km)
- Nenana Muni Airport (76 km)
- Denali 27 N (104 km)
- Fairbanks Intl Airport (117 km)
- Ester (118 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.