Frost dates for Reynolds, ID
At Reynolds, the median last spring frost (32°F) is May 21 and the median first fall frost is Sep 28, for a typical growing season of 126 days. For a 90% chance that the last frost has passed, wait until Jun 12. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 21Last spring frost (median)50% chance of 32°F after this date
- Jun 12Safer planting date10% chance of 32°F after this date
- Sep 28First 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 23 | Jun 10 | Jun 26 |
| 32°F | May 4 | May 21 | Jun 12 |
| 28°F | Apr 21 | May 5 | May 22 |
| 24°F | Apr 1 | Apr 20 | May 8 |
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 1 | Sep 15 | Sep 30 |
| 32°F | Sep 13 | Sep 28 | Oct 10 |
| 28°F | Sep 24 | Oct 8 | Oct 23 |
| 24°F | Oct 5 | Oct 22 | Nov 6 |
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 | 73 days | 95 days | 117 days |
| 32°F | 100 days | 126 days | 149 days |
| 28°F | 134 days | 156 days | 176 days |
| 24°F | 162 days | 183 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 |
|---|---|---|---|
| 83641 | 7a | 0 to 5°F | 18 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 USC00107648, at 43.2064, -116.7494, elevation 1198 m (3,930 ft).
- Data quality: Representative (10+ years), 23 years of freeze data.
- Average days per year at or below 32°F: 158.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Murphy 10 W (0 km)
- Silver City 5 W (24 km)
- Swan Falls Ph (30 km)
- Deer Flat Dam (41 km)
- Nampa Sugar Factory (46 km)
- Homedale 1 SE (47 km)
- Grand View 4 NW (51 km)
- Boise Air Terminal (57 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.