Frost dates for Silver City 5 W, ID
At Silver City 5 W, the median last spring frost (32°F) is May 31 and the median first fall frost is Oct 6, for a typical growing season of 128 days. For a 90% chance that the last frost has passed, wait until Jun 17. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 31Last spring frost (median)50% chance of 32°F after this date
- Jun 17Safer planting date10% chance of 32°F after this date
- Oct 6First fall frost (median)50% chance of 32°F by this date
- 128 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 22 | Jun 12 | Jun 28 |
| 32°F | May 4 | May 31 | Jun 17 |
| 28°F | Apr 21 | May 9 | Jun 4 |
| 24°F | Apr 3 | Apr 24 | May 16 |
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 3 | Sep 26 | Oct 12 |
| 32°F | Sep 10 | Oct 6 | Oct 25 |
| 28°F | Sep 29 | Oct 19 | Nov 6 |
| 24°F | Oct 12 | Oct 31 | Nov 17 |
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 | 75 days | 105 days | 129 days |
| 32°F | 99 days | 128 days | 159 days |
| 28°F | 128 days | 160 days | 190 days |
| 24°F | 162 days | 189 days | 217 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 |
|---|---|---|---|
| 83650 | 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 USC00108412, at 43.0022, -116.8317, elevation 1878 m (6,160 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 172.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Murphy 10 W (23 km)
- Reynolds (24 km)
- Swan Falls Ph (46 km)
- Grand View 4 NW (53 km)
- Deer Flat Dam (64 km)
- Homedale 1 SE (68 km)
- Nampa Sugar Factory (70 km)
- Boise Air Terminal (79 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.