Frost dates for Priest River Exp. Station, ID
At Priest River Exp. Station, the median last spring frost (32°F) is May 20 and the median first fall frost is Sep 13, for a typical growing season of 114 days. For a 90% chance that the last frost has passed, wait until Jun 4. Nearby ZIP codes are in USDA hardiness zones 6a to 6b.
- May 20Last spring frost (median)50% chance of 32°F after this date
- Jun 4Safer planting date10% chance of 32°F after this date
- Sep 13First fall frost (median)50% chance of 32°F by this date
- 114 daysGrowing season (median)between 32°F freezes
USDA hardiness zone 6a (-10 to -5°F) · see all zone 6a frost dates
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 6 | May 20 | Jun 4 |
| 28°F | Apr 19 | May 4 | May 17 |
| 24°F | Mar 26 | Apr 13 | May 3 |
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 | Sep 1 | Sep 13 | Sep 30 |
| 28°F | Sep 12 | Sep 28 | Oct 13 |
| 24°F | Sep 26 | Oct 10 | Nov 1 |
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 | 45 days | 74 days | 99 days |
| 32°F | 92 days | 114 days | 137 days |
| 28°F | 125 days | 146 days | 168 days |
| 24°F | 154 days | 180 days | 208 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 |
|---|---|---|---|
| 83856 | 6a | -10 to -5°F | 5 km |
| 83841 | 6b | -5 to 0°F | 17 km |
| 83821 | 6a | -10 to -5°F | 19 km |
| 99119 | 6a | -10 to -5°F | 40 km |
| 83848 | 6a | -10 to -5°F | 42 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 USC00107386, at 48.3511, -116.8353, elevation 723 m (2,371 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 190.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Sandpoint Exp. Station (21 km)
- Bayview Model Basin (46 km)
- Bonners Ferry (54 km)
- Cabinet Gorge (65 km)
- Coeur D'alene (74 km)
- Porthill 1 SW (76 km)
- Prichard 3 ESE (104 km)
- Kellogg (105 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.