Frost dates for Palmer Muni Airport, AK
At Palmer Muni Airport, the median last spring frost (32°F) is May 6 and the median first fall frost is Sep 25, for a typical growing season of 140 days. For a 90% chance that the last frost has passed, wait until May 18. Nearby ZIP codes are in USDA hardiness zones 3b to 5a.
- May 6Last spring frost (median)50% chance of 32°F after this date
- May 18Safer planting date10% chance of 32°F after this date
- Sep 25First fall frost (median)50% chance of 32°F by this date
- 140 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 9 | May 20 | May 30 |
| 32°F | Apr 24 | May 6 | May 18 |
| 28°F | Apr 12 | Apr 24 | May 6 |
| 24°F | Apr 3 | Apr 13 | Apr 26 |
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 | Sep 1 | Sep 14 | Sep 26 |
| 32°F | Sep 11 | Sep 25 | Oct 8 |
| 28°F | Sep 20 | Oct 3 | Oct 19 |
| 24°F | Oct 1 | Oct 13 | Oct 25 |
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 | 99 days | 116 days | 132 days |
| 32°F | 123 days | 140 days | 156 days |
| 28°F | 145 days | 163 days | 180 days |
| 24°F | 164 days | 183 days | 199 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 |
|---|---|---|---|
| 99645 | 5a | -20 to -15°F | 7 km |
| 99654 | 5a | -20 to -15°F | 18 km |
| 99567 | 5a | -20 to -15°F | 33 km |
| 99694 | 4a | -30 to -25°F | 39 km |
| 99688 | 3b | -35 to -30°F | 43 km |
| 99505 | 5a | -20 to -15°F | 46 km |
| 99623 | 4b | -25 to -20°F | 47 km |
| 99652 | 4a | -30 to -25°F | 48 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 USW00025331, at 61.5961, -149.0917, elevation 70 m (230 ft).
- Data quality: Representative (10+ years), 23 years of freeze data.
- Average days per year at or below 32°F: 187.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Palmer Job Corps (1 km)
- Lazy Mountain (4 km)
- Ben's Farm (5 km)
- Matanuska Exp. Farm (9 km)
- Anderson Lake (13 km)
- Little Su At Hatcher Pass Brg (15 km)
- Sutton 1 W (16 km)
- Eklutna Water Plant (20 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.