Frost dates for Cottonwood 2 WSW, ID
At Cottonwood 2 WSW, the median last spring frost (32°F) is May 6 and the median first fall frost is Oct 13, for a typical growing season of 156 days. For a 90% chance that the last frost has passed, wait until May 26. Nearby ZIP codes are in USDA hardiness zones 6a to 6b.
- May 6Last spring frost (median)50% chance of 32°F after this date
- May 26Safer planting date10% chance of 32°F after this date
- Oct 13First fall frost (median)50% chance of 32°F by this date
- 156 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 10 | May 31 | Jun 20 |
| 32°F | Apr 22 | May 6 | May 26 |
| 28°F | Apr 1 | Apr 21 | May 10 |
| 24°F | Mar 8 | Mar 30 | Apr 19 |
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 12 | Oct 1 | Oct 14 |
| 32°F | Sep 28 | Oct 13 | Oct 27 |
| 28°F | Oct 9 | Oct 24 | Nov 12 |
| 24°F | Oct 18 | Nov 5 | Nov 22 |
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 | 92 days | 119 days | 145 days |
| 32°F | 132 days | 156 days | 181 days |
| 28°F | 161 days | 188 days | 211 days |
| 24°F | 192 days | 220 days | 246 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 |
|---|---|---|---|
| 83526 | 6a | -10 to -5°F | 13 km |
| 83522 | 6b | -5 to 0°F | 15 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 USC00102159, at 46.0336, -116.3919, elevation 1202 m (3,945 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 134.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Grangeville (24 km)
- Nezperce (25 km)
- Winchester (29 km)
- Kamiah (35 km)
- Kooskia 5 SSE (36 km)
- Dworshak Fish Hatchery (52 km)
- Lewiston Nez Perce Co Airport (61 km)
- Lowell Three Rivers (63 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.