Frost dates for Silver Lake, AK
At Silver Lake, the median last spring frost (32°F) is May 31 and the median first fall frost is Sep 3, for a typical growing season of 95 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 8a.
- May 31Last spring frost (median)50% chance of 32°F after this date
- Jun 10Safer planting date10% chance of 32°F after this date
- Sep 3First fall frost (median)50% chance of 32°F by this date
- 95 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 20 | May 31 | Jun 10 |
| 28°F | May 8 | May 16 | May 27 |
| 24°F | Apr 25 | May 4 | May 13 |
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 20 | Sep 3 | Sep 17 |
| 28°F | Sep 4 | Sep 17 | Sep 29 |
| 24°F | Sep 13 | Sep 28 | Oct 12 |
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 | 64 days | 83 days |
| 32°F | 77 days | 95 days | 111 days |
| 28°F | 106 days | 121 days | 138 days |
| 24°F | 129 days | 145 days | 163 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 |
|---|---|---|---|
| 99573 | 4b | -25 to -20°F | 79 km |
| 99566 | 4b | -25 to -20°F | 89 km |
| 99686 | 5a | -20 to -15°F | 119 km |
| 99586 | 2b | -45 to -40°F | 130 km |
| 99677 | 8a | 10 to 15°F | 150 km |
| 99764 | 2a | -50 to -45°F | 179 km |
| 99588 | 2b | -45 to -40°F | 187 km |
| 99574 | 5a | -20 to -15°F | 188 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 USC00508470, at 61.5175, -144.1914, elevation 366 m (1,200 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 246.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Tonsina (54 km)
- McCarthy 3 SW (64 km)
- Gennallen Kcam (96 km)
- Gulkana Airport (98 km)
- Nabesna (116 km)
- Valdez WSO (123 km)
- Valdez (125 km)
- Cordova M K Smith Airport (133 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.