Frost dates for American Falls 6 NE, ID
At American Falls 6 NE, the median last spring frost (32°F) is May 14 and the median first fall frost is Oct 2, for a typical growing season of 138 days. For a 90% chance that the last frost has passed, wait until Jun 4. Nearby ZIP codes are in USDA hardiness zones 5b to 6b.
- May 14Last spring frost (median)50% chance of 32°F after this date
- Jun 4Safer planting date10% chance of 32°F after this date
- Oct 2First fall frost (median)50% chance of 32°F by this date
- 138 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 17 | Jun 5 | Jun 21 |
| 32°F | Apr 30 | May 14 | Jun 4 |
| 28°F | Apr 12 | Apr 29 | May 14 |
| 24°F | Mar 21 | Apr 11 | May 1 |
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 2 | Sep 20 | Oct 3 |
| 32°F | Sep 16 | Oct 2 | Oct 17 |
| 28°F | Sep 29 | Oct 16 | Nov 2 |
| 24°F | Oct 14 | Oct 30 | Nov 13 |
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 | 80 days | 104 days | 127 days |
| 32°F | 112 days | 138 days | 161 days |
| 28°F | 142 days | 168 days | 191 days |
| 24°F | 175 days | 198 days | 221 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 |
|---|---|---|---|
| 83210 | 5b | -15 to -10°F | 18 km |
| 83211 | 6a | -10 to -5°F | 28 km |
| 83277 | 5b | -15 to -10°F | 29 km |
| 83204 | 6a | -10 to -5°F | 30 km |
| 83209 | 6a | -10 to -5°F | 37 km |
| 83262 | 5b | -15 to -10°F | 40 km |
| 83203 | 5b | -15 to -10°F | 41 km |
| 83201 | 6b | -5 to 0°F | 42 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 USC00100227, at 42.8572, -112.8800, elevation 1346 m (4,415 ft).
- Data quality: Representative (10+ years), 18 years of freeze data.
- Average days per year at or below 32°F: 155.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- American Falls (9 km)
- Aberdeen Exp. Station (12 km)
- Massacre Rocks State Park (23 km)
- Pocatello Regional Airport (26 km)
- Pocatello City (35 km)
- Pocatello 2 NE (39 km)
- Fort Hall 1 NNE (43 km)
- Minidoka Dam (55 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.