Frost dates for Twin Falls-Kmvt, ID
At Twin Falls-Kmvt, the median last spring frost (32°F) is Apr 30 and the median first fall frost is Oct 9, for a typical growing season of 161 days. For a 90% chance that the last frost has passed, wait until May 14. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- Apr 30Last spring frost (median)50% chance of 32°F after this date
- May 14Safer planting date10% chance of 32°F after this date
- Oct 9First fall frost (median)50% chance of 32°F by this date
- 161 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 1 | May 14 | Jun 2 |
| 32°F | Apr 17 | Apr 30 | May 14 |
| 28°F | Mar 30 | Apr 17 | Apr 30 |
| 24°F | Mar 4 | Mar 28 | Apr 17 |
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 12 | Sep 28 | Oct 12 |
| 32°F | Sep 24 | Oct 9 | Oct 24 |
| 28°F | Oct 7 | Oct 23 | Nov 5 |
| 24°F | Oct 19 | Nov 3 | Nov 19 |
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 | 112 days | 136 days | 156 days |
| 32°F | 140 days | 161 days | 181 days |
| 28°F | 166 days | 187 days | 211 days |
| 24°F | 193 days | 220 days | 248 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 83328 | 7a | 0 to 5°F | 13 km |
| 83338 | 6b | -5 to 0°F | 17 km |
| 83341 | 6b | -5 to 0°F | 17 km |
| 83325 | 6b | -5 to 0°F | 18 km |
| 83301 | 6b | -5 to 0°F | 21 km |
| 83334 | 6b | -5 to 0°F | 22 km |
| 83355 | 6b | -5 to 0°F | 29 km |
| 83335 | 6b | -5 to 0°F | 31 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 USC00109293, at 42.5808, -114.4569, elevation 1119 m (3,670 ft).
- Data quality: Representative (10+ years), 15 years of freeze data.
- Average days per year at or below 32°F: 140.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Twin Falls 6 E (10 km)
- Twin Falls Sun Valley Regional Airport (11 km)
- Jerome Co Airport (16 km)
- Jerome (18 km)
- Buhl #2 (24 km)
- Hazelton (26 km)
- Castleford 2 N (34 km)
- Shoshone 1 WNW (40 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.