Frost dates for Idaho Falls - Kifi, ID
At Idaho Falls - Kifi, the median last spring frost (32°F) is May 9 and the median first fall frost is Oct 1, for a typical growing season of 142 days. For a 90% chance that the last frost has passed, wait until Jun 2. Nearby ZIP codes are in USDA hardiness zone 5b.
- May 9Last spring frost (median)50% chance of 32°F after this date
- Jun 2Safer planting date10% chance of 32°F after this date
- Oct 1First fall frost (median)50% chance of 32°F by this date
- 142 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 10 | May 30 | Jun 16 |
| 32°F | Apr 27 | May 9 | Jun 2 |
| 28°F | Apr 11 | Apr 28 | May 11 |
| 24°F | Mar 20 | Apr 11 | Apr 29 |
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 4 | Sep 20 | Oct 3 |
| 32°F | Sep 17 | Oct 1 | Oct 15 |
| 28°F | Sep 27 | Oct 13 | Oct 27 |
| 24°F | Oct 9 | Oct 25 | Nov 8 |
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 | 87 days | 113 days | 135 days |
| 32°F | 117 days | 142 days | 163 days |
| 28°F | 147 days | 168 days | 189 days |
| 24°F | 173 days | 197 days | 218 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 |
|---|---|---|---|
| 83404 | 5b | -15 to -10°F | 10 km |
| 83406 | 5b | -15 to -10°F | 10 km |
| 83401 | 5b | -15 to -10°F | 11 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 USC00104455, at 43.5139, -112.0125, elevation 1445 m (4,742 ft).
- Data quality: Standard (24+ years of data), 24 years of freeze data.
- Average days per year at or below 32°F: 166.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Idaho Falls Fanning Field (4 km)
- Rigby (20 km)
- Idaho Falls 16 SE (26 km)
- Rexburg Byu Idaho (37 km)
- Rexburg Madison Co Airport (39 km)
- Blackfoot Fire Dept (45 km)
- Sugar City (47 km)
- Hamer 4 NW (54 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.