Frost dates for Huntley Exp. Station, MT
At Huntley Exp. Station, the median last spring frost (32°F) is May 12 and the median first fall frost is Sep 25, for a typical growing season of 136 days. For a 90% chance that the last frost has passed, wait until May 26. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 12Last spring frost (median)50% chance of 32°F after this date
- May 26Safer planting date10% chance of 32°F after this date
- Sep 25First fall frost (median)50% chance of 32°F by this date
- 136 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 13 | May 25 | Jun 10 |
| 32°F | Apr 30 | May 12 | May 26 |
| 28°F | Apr 15 | Apr 30 | May 14 |
| 24°F | Apr 3 | Apr 19 | May 2 |
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 1 | Sep 14 | Sep 29 |
| 32°F | Sep 13 | Sep 25 | Oct 8 |
| 28°F | Sep 23 | Oct 4 | Oct 18 |
| 24°F | Oct 1 | Oct 15 | Oct 29 |
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 | 91 days | 111 days | 128 days |
| 32°F | 117 days | 136 days | 153 days |
| 28°F | 138 days | 157 days | 176 days |
| 24°F | 158 days | 178 days | 200 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 |
|---|---|---|---|
| 59037 | 4b | -25 to -20°F | 7 km |
| 59006 | 4b | -25 to -20°F | 12 km |
| 59079 | 4b | -25 to -20°F | 18 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 USC00244345, at 45.9228, -108.2453, elevation 925 m (3,034 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 182.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Billings Water Plant (25 km)
- Billings Logan Intl Airport (26 km)
- Billings WFO (32 km)
- Pompeys Pillar 15n (36 km)
- Hardin (54 km)
- Roundup 15 SW (59 km)
- Roundup (61 km)
- Yellowtail Dam (72 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.