Frost dates for Potlatch 3 NNE, ID
At Potlatch 3 NNE, the median last spring frost (32°F) is May 15 and the median first fall frost is Sep 21, for a typical growing season of 126 days. For a 90% chance that the last frost has passed, wait until Jun 2. Nearby ZIP codes are in USDA hardiness zone 6b.
- May 15Last spring frost (median)50% chance of 32°F after this date
- Jun 2Safer planting date10% chance of 32°F after this date
- Sep 21First 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 21 | Jun 10 | Jul 5 |
| 32°F | Apr 30 | May 15 | Jun 2 |
| 28°F | Apr 4 | Apr 28 | May 13 |
| 24°F | Mar 7 | Mar 30 | Apr 27 |
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 15 | Sep 3 | Sep 21 |
| 32°F | Aug 31 | Sep 21 | Oct 7 |
| 28°F | Sep 18 | Oct 5 | Oct 27 |
| 24°F | Oct 1 | Oct 20 | Nov 14 |
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 | 52 days | 84 days | 112 days |
| 32°F | 97 days | 126 days | 149 days |
| 28°F | 137 days | 162 days | 192 days |
| 24°F | 171 days | 203 days | 234 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 |
|---|---|---|---|
| 83855 | 6b | -5 to 0°F | 5 km |
| 83857 | 6b | -5 to 0°F | 9 km |
| 83834 | 6b | -5 to 0°F | 11 km |
| 83824 | 6b | -5 to 0°F | 18 km |
| 83870 | 6b | -5 to 0°F | 20 km |
| 99128 | 6b | -5 to 0°F | 23 km |
| 99130 | 6b | -5 to 0°F | 25 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 USC00107301, at 46.9603, -116.8550, elevation 841 m (2,760 ft).
- Data quality: Representative (10+ years), 27 years of freeze data.
- Average days per year at or below 32°F: 152.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Moscow U Of I (27 km)
- Plummer 3 WSW (40 km)
- Saint Maries (45 km)
- Elk River (55 km)
- Dworshak Fish Hatchery (65 km)
- Lewiston Nez Perce Co Airport (66 km)
- Coeur D'alene (80 km)
- Winchester (82 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.