Frost dates for Skq Dam, MT
At Skq Dam, the median last spring frost (32°F) is May 15 and the median first fall frost is Sep 28, for a typical growing season of 134 days. For a 90% chance that the last frost has passed, wait until Jun 1. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 15Last spring frost (median)50% chance of 32°F after this date
- Jun 1Safer planting date10% chance of 32°F after this date
- Sep 28First fall frost (median)50% chance of 32°F by this date
- 134 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 2 | Jun 21 |
| 32°F | May 3 | May 15 | Jun 1 |
| 28°F | Apr 17 | May 2 | May 17 |
| 24°F | Mar 27 | Apr 14 | 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 15 | Sep 29 |
| 32°F | Sep 13 | Sep 28 | Oct 11 |
| 28°F | Sep 24 | Oct 8 | Oct 24 |
| 24°F | Oct 4 | Oct 22 | Nov 6 |
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 | 103 days | 126 days |
| 32°F | 112 days | 134 days | 152 days |
| 28°F | 137 days | 158 days | 178 days |
| 24°F | 165 days | 189 days | 214 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 |
|---|---|---|---|
| 59910 | 6a | -10 to -5°F | 16 km |
| 59915 | 6a | -10 to -5°F | 20 km |
| 59845 | 6a | -10 to -5°F | 23 km |
| 59848 | 6a | -10 to -5°F | 34 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 USC00246640, at 47.6775, -114.2419, elevation 832 m (2,730 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 153.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Polson (4 km)
- Bigfork 13 S (27 km)
- Swan Lake (40 km)
- Saint Ignatius (42 km)
- Lindbergh Lake (50 km)
- Creston (57 km)
- Kalispell Glacier Airport (70 km)
- Superior (73 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.