Frost dates for Rexburg Byu Idaho, ID
At Rexburg Byu Idaho, the median last spring frost (32°F) is May 12 and the median first fall frost is Sep 24, for a typical growing season of 132 days. For a 90% chance that the last frost has passed, wait until Jun 2. Nearby ZIP codes are in USDA hardiness zone 5a.
- May 12Last spring frost (median)50% chance of 32°F after this date
- Jun 2Safer planting date10% chance of 32°F after this date
- Sep 24First fall frost (median)50% chance of 32°F by this date
- 132 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 16 | Jun 4 | Jun 22 |
| 32°F | Apr 29 | May 12 | Jun 2 |
| 28°F | Apr 12 | Apr 30 | May 14 |
| 24°F | Mar 29 | Apr 15 | May 4 |
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 28 | Sep 11 | Sep 25 |
| 32°F | Sep 6 | Sep 24 | Oct 8 |
| 28°F | Sep 20 | Oct 7 | Oct 21 |
| 24°F | Oct 2 | Oct 20 | Nov 4 |
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 | 98 days | 121 days |
| 32°F | 107 days | 132 days | 154 days |
| 28°F | 137 days | 161 days | 181 days |
| 24°F | 161 days | 187 days | 209 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 |
|---|---|---|---|
| 83460 | 5a | -20 to -15°F | 1 km |
| 83440 | 5a | -20 to -15°F | 2 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 USC00107644, at 43.8083, -111.7892, elevation 1526 m (5,005 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 184.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Rexburg Madison Co Airport (3 km)
- Sugar City (10 km)
- Rigby (18 km)
- Saint Anthony (18 km)
- Idaho Falls - Kifi (37 km)
- Idaho Falls Fanning Field (39 km)
- Ashton 1n (40 km)
- Tetonia Exp. Station (41 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.