Frost dates for Small 6n, ID
At Small 6n, the median last spring frost (32°F) is Jun 5 and the median first fall frost is Sep 20, for a typical growing season of 106 days. For a 90% chance that the last frost has passed, wait until Jun 21. Nearby ZIP codes are in USDA hardiness zone 5b.
- Jun 5Last spring frost (median)50% chance of 32°F after this date
- Jun 21Safer planting date10% chance of 32°F after this date
- Sep 20First fall frost (median)50% chance of 32°F by this date
- 106 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 | Jun 5 | Jun 18 | Jul 2 |
| 32°F | May 11 | Jun 5 | Jun 21 |
| 28°F | Apr 25 | May 10 | Jun 8 |
| 24°F | Apr 9 | Apr 24 | May 9 |
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 | Aug 25 | Sep 8 | Sep 23 |
| 32°F | Sep 3 | Sep 20 | Oct 4 |
| 28°F | Sep 14 | Oct 2 | Oct 15 |
| 24°F | Sep 28 | Oct 13 | Oct 27 |
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 | 58 days | 79 days | 99 days |
| 32°F | 81 days | 106 days | 133 days |
| 28°F | 113 days | 143 days | 163 days |
| 24°F | 148 days | 169 days | 191 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 |
|---|---|---|---|
| 83423 | 5b | -15 to -10°F | 9 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 USC00108500, at 44.2964, -112.4094, elevation 1750 m (5,740 ft).
- Data quality: Estimated from nearby stations (2+ years), 10 years of freeze data.
- Average days per year at or below 32°F: 191.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Dubois Exp. Station (18 km)
- Monteview (32 km)
- Hamer 4 NW (38 km)
- Saint Anthony (70 km)
- Sugar City (70 km)
- Rexburg Madison Co Airport (71 km)
- Rexburg Byu Idaho (73 km)
- Howe (74 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.