Frost dates for Grand Rpds Forest Lab, MN
At Grand Rpds Forest Lab, the median last spring frost (32°F) is May 17 and the median first fall frost is Sep 24, for a typical growing season of 130 days. For a 90% chance that the last frost has passed, wait until May 31. Nearby ZIP codes are in USDA hardiness zones 3b to 4a.
- May 17Last spring frost (median)50% chance of 32°F after this date
- May 31Safer planting date10% chance of 32°F after this date
- Sep 24First fall frost (median)50% chance of 32°F by this date
- 130 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 16 | May 29 | Jun 13 |
| 32°F | May 3 | May 17 | May 31 |
| 28°F | Apr 24 | May 6 | May 19 |
| 24°F | Apr 12 | Apr 26 | May 11 |
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 30 | Sep 15 | Sep 27 |
| 32°F | Sep 10 | Sep 24 | Oct 7 |
| 28°F | Sep 20 | Oct 5 | Oct 20 |
| 24°F | Oct 1 | Oct 18 | Nov 3 |
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 | 86 days | 107 days | 125 days |
| 32°F | 110 days | 130 days | 149 days |
| 28°F | 132 days | 152 days | 170 days |
| 24°F | 152 days | 173 days | 194 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 |
|---|---|---|---|
| 55744 | 4a | -30 to -25°F | 2 km |
| 55722 | 4a | -30 to -25°F | 6 km |
| 55786 | 4a | -30 to -25°F | 12 km |
| 55764 | 4a | -30 to -25°F | 18 km |
| 55716 | 4a | -30 to -25°F | 20 km |
| 55709 | 3b | -35 to -30°F | 20 km |
| 55793 | 4a | -30 to -25°F | 21 km |
| 55742 | 4a | -30 to -25°F | 28 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 USC00213303, at 47.2436, -93.4975, elevation 399 m (1,310 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 187.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Pokegama Dam (7 km)
- Marcell 5ne (45 km)
- Sandy Lake Dam Libby (52 km)
- Hibbing Chisholm Hibbing Airport (52 km)
- Leech Lake (55 km)
- Floodwood 3 NE (56 km)
- Wright 3 E (75 km)
- Eveleth Wastewater Plant (77 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.