Frost dates for Rothsay, MN
At Rothsay, the median last spring frost (32°F) is May 5 and the median first fall frost is Oct 3, for a typical growing season of 149 days. For a 90% chance that the last frost has passed, wait until May 20. Nearby ZIP codes are in USDA hardiness zone 4a.
- May 5Last spring frost (median)50% chance of 32°F after this date
- May 20Safer planting date10% chance of 32°F after this date
- Oct 3First fall frost (median)50% chance of 32°F by this date
- 149 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 3 | May 15 | May 30 |
| 32°F | Apr 24 | May 5 | May 20 |
| 28°F | Apr 13 | Apr 28 | May 10 |
| 24°F | Apr 5 | 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 12 | Sep 25 | Oct 6 |
| 32°F | Sep 21 | Oct 3 | Oct 17 |
| 28°F | Sep 28 | Oct 12 | Oct 25 |
| 24°F | Oct 5 | Oct 21 | Nov 4 |
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 | 113 days | 131 days | 149 days |
| 32°F | 131 days | 149 days | 166 days |
| 28°F | 148 days | 166 days | 187 days |
| 24°F | 164 days | 184 days | 206 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 |
|---|---|---|---|
| 56579 | 4a | -30 to -25°F | 4 km |
| 56572 | 4a | -30 to -25°F | 21 km |
| 56534 | 4a | -30 to -25°F | 21 km |
| 56514 | 4a | -30 to -25°F | 22 km |
| 56594 | 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 USC00217149, at 46.4808, -96.2869, elevation 367 m (1,204 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 171.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Fergus Falls (25 km)
- Breckenridge 3e (27 km)
- Detroit Lakes 1 NNE (52 km)
- Ottertail (57 km)
- Moorhead (57 km)
- Detroit Lakes 12e (67 km)
- New York Mills (69 km)
- Tamarac Wildlife Re (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.