Frost dates for Moose Pass 3nw, AK
At Moose Pass 3nw, the median last spring frost (32°F) is May 31 and the median first fall frost is Sep 8, for a typical growing season of 99 days. For a 90% chance that the last frost has passed, wait until Jun 15. Nearby ZIP codes are in USDA hardiness zone 5a.
- May 31Last spring frost (median)50% chance of 32°F after this date
- Jun 15Safer planting date10% chance of 32°F after this date
- Sep 8First fall frost (median)50% chance of 32°F by this date
- 99 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 19 | May 31 | Jun 15 |
| 28°F | Apr 30 | May 14 | May 28 |
| 24°F | Apr 13 | Apr 29 | May 12 |
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 24 | Sep 8 | Sep 25 |
| 28°F | Sep 4 | Sep 22 | Oct 6 |
| 24°F | Sep 18 | Oct 2 | Oct 20 |
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 | 40 days | 67 days | 90 days |
| 32°F | 80 days | 99 days | 120 days |
| 28°F | 109 days | 129 days | 150 days |
| 24°F | 136 days | 158 days | 179 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 |
|---|---|---|---|
| 99631 | 5a | -20 to -15°F | 16 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 USC00505894, at 60.5028, -149.4261, elevation 150 m (492 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 197.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Seward 19n (17 km)
- Cooper Lake Project (18 km)
- Cooper Landing 5 W (30 km)
- Seward 8 NW (37 km)
- Seward Airport (42 km)
- Portage Glacier V C (45 km)
- Hope (45 km)
- Whittier (51 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.