Frost dates for Winona Dam 5 A, MN
At Winona Dam 5 A, the median last spring frost (32°F) is Apr 23 and the median first fall frost is Oct 21, for a typical growing season of 180 days. For a 90% chance that the last frost has passed, wait until May 6. Nearby ZIP codes are in USDA hardiness zones 4b to 5a.
- Apr 23Last spring frost (median)50% chance of 32°F after this date
- May 6Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 180 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 | Apr 18 | May 3 | May 16 |
| 32°F | Apr 7 | Apr 23 | May 6 |
| 28°F | Mar 30 | Apr 11 | Apr 27 |
| 24°F | Mar 18 | Apr 3 | Apr 18 |
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 27 | Oct 10 | Oct 23 |
| 32°F | Oct 7 | Oct 21 | Nov 4 |
| 28°F | Oct 19 | Nov 1 | Nov 15 |
| 24°F | Oct 30 | Nov 9 | Nov 24 |
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 | 141 days | 159 days | 178 days |
| 32°F | 161 days | 180 days | 201 days |
| 28°F | 180 days | 201 days | 222 days |
| 24°F | 201 days | 220 days | 240 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 54629 | 4b | -25 to -20°F | 10 km |
| 55959 | 4b | -25 to -20°F | 11 km |
| 55987 | 5a | -20 to -15°F | 11 km |
| 54625 | 4b | -25 to -20°F | 13 km |
| 55969 | 4b | -25 to -20°F | 16 km |
| 54661 | 5a | -20 to -15°F | 17 km |
| 55952 | 4b | -25 to -20°F | 21 km |
| 54622 | 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 USC00219072, at 44.0875, -91.6703, elevation 202 m (663 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 148.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Winona (6 km)
- Minnesota City Dam 5 (14 km)
- Rushford (32 km)
- La Crescent Dam 7 (38 km)
- Theilman 1ssw (47 km)
- Caledonia (53 km)
- Preston (56 km)
- Mabel (63 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.