Frost dates for Garden Valley, ID
At Garden Valley, the median last spring frost (32°F) is Jun 1 and the median first fall frost is Sep 10, for a typical growing season of 102 days. For a 90% chance that the last frost has passed, wait until Jun 20. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- Jun 1Last spring frost (median)50% chance of 32°F after this date
- Jun 20Safer planting date10% chance of 32°F after this date
- Sep 10First fall frost (median)50% chance of 32°F by this date
- 102 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 |
|---|---|---|---|
| 32°F | May 13 | Jun 1 | Jun 20 |
| 28°F | Apr 26 | May 11 | May 30 |
| 24°F | Mar 29 | Apr 22 | May 11 |
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 | Aug 28 | Sep 10 | Sep 27 |
| 28°F | Sep 8 | Sep 24 | Oct 10 |
| 24°F | Sep 22 | Oct 8 | Oct 29 |
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 | 40 days | 67 days | 91 days |
| 32°F | 76 days | 102 days | 125 days |
| 28°F | 112 days | 136 days | 159 days |
| 24°F | 143 days | 171 days | 203 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 |
|---|---|---|---|
| 83622 | 6b | -5 to 0°F | 7 km |
| 83602 | 7a | 0 to 5°F | 14 km |
| 83666 | 6b | -5 to 0°F | 16 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 USC00103448, at 44.1011, -115.9694, elevation 945 m (3,100 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 180.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ola (26 km)
- Lowman (28 km)
- Idaho City (31 km)
- Boise 7 N (44 km)
- Cascade 1 NW (47 km)
- Emmett 2 E (48 km)
- Deadwood Lodge (51 km)
- Arrowrock Dam (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.