Frost dates for Preston, MN
At Preston, the median last spring frost (32°F) is May 14 and the median first fall frost is Sep 28, for a typical growing season of 136 days. For a 90% chance that the last frost has passed, wait until May 27. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 14Last spring frost (median)50% chance of 32°F after this date
- May 27Safer planting date10% chance of 32°F after this date
- Sep 28First fall frost (median)50% chance of 32°F by this date
- 136 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 10 | May 24 | Jun 4 |
| 32°F | May 1 | May 14 | May 27 |
| 28°F | Apr 21 | May 4 | May 18 |
| 24°F | Apr 8 | Apr 23 | May 7 |
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 5 | Sep 19 | Oct 2 |
| 32°F | Sep 15 | Sep 28 | Oct 9 |
| 28°F | Sep 24 | Oct 5 | Oct 18 |
| 24°F | Oct 4 | Oct 16 | Oct 29 |
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 | 98 days | 117 days | 135 days |
| 32°F | 118 days | 136 days | 153 days |
| 28°F | 137 days | 154 days | 173 days |
| 24°F | 157 days | 175 days | 195 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 |
|---|---|---|---|
| 55965 | 4b | -25 to -20°F | 7 km |
| 55935 | 4b | -25 to -20°F | 9 km |
| 55949 | 4b | -25 to -20°F | 12 km |
| 55939 | 4b | -25 to -20°F | 14 km |
| 55990 | 4b | -25 to -20°F | 16 km |
| 55923 | 4b | -25 to -20°F | 22 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 USC00216654, at 43.6725, -92.0747, elevation 284 m (930 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 166.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Rushford (30 km)
- Mabel (30 km)
- Grand Meadow (40 km)
- Rochester Intl Airport (42 km)
- Caledonia (46 km)
- Winona (54 km)
- Winona Dam 5 A (56 km)
- Minnesota City Dam 5 (58 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.