Frost dates for Thorhult, MN
At Thorhult, the median last spring frost (32°F) is May 24 and the median first fall frost is Sep 20, for a typical growing season of 120 days. For a 90% chance that the last frost has passed, wait until Jun 7. Nearby ZIP codes are in USDA hardiness zone 3b.
- May 24Last spring frost (median)50% chance of 32°F after this date
- Jun 7Safer planting date10% chance of 32°F after this date
- Sep 20First fall frost (median)50% chance of 32°F by this date
- 120 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 20 | Jun 2 | Jun 23 |
| 32°F | May 7 | May 24 | Jun 7 |
| 28°F | Apr 27 | May 12 | May 29 |
| 24°F | Apr 15 | Apr 29 | May 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 | Aug 22 | Sep 8 | Sep 24 |
| 32°F | Sep 4 | Sep 20 | Oct 3 |
| 28°F | Sep 15 | Oct 1 | Oct 15 |
| 24°F | Sep 24 | Oct 12 | Oct 27 |
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 | 70 days | 95 days | 116 days |
| 32°F | 96 days | 120 days | 142 days |
| 28°F | 119 days | 141 days | 161 days |
| 24°F | 140 days | 163 days | 184 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 |
|---|---|---|---|
| 56727 | 3b | -35 to -30°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 USC00218254, at 48.2108, -95.2475, elevation 377 m (1,237 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 192.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Red Lake Indian Agcy (41 km)
- Camp Norris Dnr (45 km)
- Goodridge 12 NNW (48 km)
- Agassiz Refuge (55 km)
- Waskish 4ne (61 km)
- Thief River Falls 2 (70 km)
- Baudette Intl Airport (74 km)
- Baudette (74 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.