Frost dates for Stillwater 2sw, MN
At Stillwater 2sw, the median last spring frost (32°F) is Apr 30 and the median first fall frost is Oct 11, for a typical growing season of 163 days. For a 90% chance that the last frost has passed, wait until May 13. Nearby ZIP codes are in USDA hardiness zones 4b to 5a.
- Apr 30Last spring frost (median)50% chance of 32°F after this date
- May 13Safer planting date10% chance of 32°F after this date
- Oct 11First fall frost (median)50% chance of 32°F by this date
- 163 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 26 | May 8 | May 23 |
| 32°F | Apr 17 | Apr 30 | May 13 |
| 28°F | Apr 6 | Apr 20 | May 2 |
| 24°F | Mar 29 | Apr 9 | Apr 24 |
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 20 | Oct 2 | Oct 14 |
| 32°F | Sep 28 | Oct 11 | Oct 23 |
| 28°F | Oct 10 | Oct 23 | Nov 4 |
| 24°F | Oct 19 | Nov 1 | Nov 14 |
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 | 127 days | 145 days | 163 days |
| 32°F | 143 days | 163 days | 181 days |
| 28°F | 165 days | 184 days | 203 days |
| 24°F | 184 days | 203 days | 222 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 |
|---|---|---|---|
| 55082 | 4b | -25 to -20°F | 3 km |
| 55042 | 5a | -20 to -15°F | 7 km |
| 55115 | 5a | -20 to -15°F | 8 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 USC00218039, at 45.0456, -92.8522, elevation 274 m (898 ft).
- Data quality: Representative (10+ years), 14 years of freeze data.
- Average days per year at or below 32°F: 159.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Stillwater 1 SE (4 km)
- St. Paul (18 km)
- Vadnais Lake (19 km)
- St. Paul Downtown Airport (20 km)
- U Of Mn St. Paul (26 km)
- St. Paul 3sw (27 km)
- Hastings Dam 2 (32 km)
- Lower St. Anthony Falls (32 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.