Frost dates for Theilman 1ssw, MN
At Theilman 1ssw, the median last spring frost (32°F) is May 7 and the median first fall frost is Oct 2, for a typical growing season of 148 days. For a 90% chance that the last frost has passed, wait until May 22. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 7Last spring frost (median)50% chance of 32°F after this date
- May 22Safer planting date10% chance of 32°F after this date
- Oct 2First fall frost (median)50% chance of 32°F by this date
- 148 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 4 | May 16 | May 30 |
| 32°F | Apr 24 | May 7 | May 22 |
| 28°F | Apr 13 | Apr 28 | May 12 |
| 24°F | Apr 1 | Apr 18 | May 3 |
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 26 | Oct 6 |
| 32°F | Sep 20 | Oct 2 | Oct 15 |
| 28°F | Sep 27 | Oct 12 | Oct 25 |
| 24°F | Oct 6 | Oct 23 | Nov 5 |
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 | 111 days | 131 days | 147 days |
| 32°F | 128 days | 148 days | 166 days |
| 28°F | 146 days | 167 days | 187 days |
| 24°F | 164 days | 189 days | 208 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 |
|---|---|---|---|
| 55957 | 4b | -25 to -20°F | 9 km |
| 55945 | 4b | -25 to -20°F | 11 km |
| 55964 | 4b | -25 to -20°F | 14 km |
| 55968 | 4b | -25 to -20°F | 15 km |
| 55932 | 4b | -25 to -20°F | 17 km |
| 55041 | 4b | -25 to -20°F | 17 km |
| 55991 | 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 USC00218227, at 44.2811, -92.1944, elevation 230 m (753 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 170.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Minnesota City Dam 5 (33 km)
- Zumbrota (38 km)
- Byron 4north (41 km)
- Winona Dam 5 A (47 km)
- Rochester Intl Airport (48 km)
- Red Wing Dam 3 (49 km)
- Winona (52 km)
- Rushford (64 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.