Frost dates for Willow West, AK
At Willow West, the median last spring frost (32°F) is May 15 and the median first fall frost is Sep 18, for a typical growing season of 126 days. For a 90% chance that the last frost has passed, wait until May 28. Nearby ZIP codes are in USDA hardiness zone 3b.
- May 15Last spring frost (median)50% chance of 32°F after this date
- May 28Safer planting date10% chance of 32°F after this date
- Sep 18First fall frost (median)50% chance of 32°F by this date
- 126 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 15 | May 28 | Jun 9 |
| 32°F | May 3 | May 15 | May 28 |
| 28°F | Apr 21 | May 3 | May 17 |
| 24°F | Apr 12 | Apr 24 | May 6 |
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 25 | Sep 7 | Sep 20 |
| 32°F | Sep 4 | Sep 18 | Sep 28 |
| 28°F | Sep 14 | Sep 27 | Oct 9 |
| 24°F | Sep 23 | Oct 5 | Oct 19 |
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 | 83 days | 100 days | 119 days |
| 32°F | 107 days | 126 days | 145 days |
| 28°F | 127 days | 146 days | 165 days |
| 24°F | 146 days | 165 days | 184 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 |
|---|---|---|---|
| 99688 | 3b | -35 to -30°F | 28 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 USC00509861, at 61.7481, -150.0542, elevation 62 m (205 ft).
- Data quality: Representative (10+ years), 14 years of freeze data.
- Average days per year at or below 32°F: 219.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Whites Crossing (5 km)
- Anderson Lake (40 km)
- Little Su At Hatcher Pass Brg (44 km)
- Matanuska Exp. Farm (47 km)
- Eklutna Water Plant (51 km)
- Ben's Farm (52 km)
- Palmer Job Corps (53 km)
- Palmer Muni Airport (54 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.