Frost dates for Big River Lakes, AK
At Big River Lakes, the median last spring frost (32°F) is May 7 and the median first fall frost is Oct 7, for a typical growing season of 151 days. For a 90% chance that the last frost has passed, wait until May 25. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 7Last spring frost (median)50% chance of 32°F after this date
- May 25Safer planting date10% chance of 32°F after this date
- Oct 7First fall frost (median)50% chance of 32°F by this date
- 151 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 7 | May 22 | Jun 5 |
| 32°F | Apr 21 | May 7 | May 25 |
| 28°F | Apr 8 | Apr 23 | May 9 |
| 24°F | Apr 1 | Apr 11 | Apr 28 |
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 7 | Sep 26 | Oct 11 |
| 32°F | Sep 20 | Oct 7 | Oct 22 |
| 28°F | Oct 1 | Oct 19 | Nov 1 |
| 24°F | Oct 12 | Oct 27 | Nov 11 |
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 | 102 days | 125 days | 146 days |
| 32°F | 129 days | 151 days | 173 days |
| 28°F | 153 days | 176 days | 197 days |
| 24°F | 175 days | 198 days | 218 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 |
|---|---|---|---|
| 99635 | 4b | -25 to -20°F | 47 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 USC00500788, at 60.8142, -152.2970, elevation 18 m (60 ft).
- Data quality: Representative (10+ years), 15 years of freeze data.
- Average days per year at or below 32°F: 184.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Kenai 9n (55 km)
- Kenai Muni Airport (63 km)
- Soldotna 5ssw (77 km)
- Sterling 6sw (83 km)
- Kenai 29 ENE (101 km)
- Homer 8 NW (124 km)
- Anchorage Intl Airport (129 km)
- Port Alsworth (130 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.