Frost dates for Matanuska Exp. Farm, AK
At Matanuska Exp. Farm, the median last spring frost (32°F) is May 14 and the median first fall frost is Sep 20, for a typical growing season of 127 days. For a 90% chance that the last frost has passed, wait until May 26. Nearby ZIP codes are in USDA hardiness zones 3b to 5a.
- May 14Last spring frost (median)50% chance of 32°F after this date
- May 26Safer planting date10% chance of 32°F after this date
- Sep 20First fall frost (median)50% chance of 32°F by this date
- 127 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 17 | May 28 | Jun 6 |
| 32°F | May 3 | May 14 | May 26 |
| 28°F | Apr 17 | May 1 | May 13 |
| 24°F | Apr 5 | Apr 18 | May 1 |
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 27 | Sep 8 | Sep 20 |
| 32°F | Sep 6 | Sep 20 | Oct 1 |
| 28°F | Sep 18 | Oct 1 | Oct 15 |
| 24°F | Sep 28 | Oct 10 | 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 | 85 days | 102 days | 118 days |
| 32°F | 109 days | 127 days | 144 days |
| 28°F | 133 days | 152 days | 171 days |
| 24°F | 156 days | 175 days | 194 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 |
|---|---|---|---|
| 99654 | 5a | -20 to -15°F | 10 km |
| 99645 | 5a | -20 to -15°F | 16 km |
| 99694 | 4a | -30 to -25°F | 31 km |
| 99567 | 5a | -20 to -15°F | 32 km |
| 99505 | 5a | -20 to -15°F | 38 km |
| 99623 | 4b | -25 to -20°F | 38 km |
| 99652 | 4a | -30 to -25°F | 39 km |
| 99688 | 3b | -35 to -30°F | 41 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 USC00505733, at 61.5664, -149.2542, elevation 52 m (172 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 194.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ben's Farm (5 km)
- Anderson Lake (8 km)
- Palmer Job Corps (9 km)
- Palmer Muni Airport (9 km)
- Lazy Mountain (13 km)
- Eklutna Water Plant (14 km)
- Little Su At Hatcher Pass Brg (16 km)
- Sutton 1 W (25 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.