Frost dates for Stephenson 5wsw, MI
At Stephenson 5wsw, the median last spring frost (32°F) is May 22 and the median first fall frost is Sep 27, for a typical growing season of 126 days. For a 90% chance that the last frost has passed, wait until Jun 4. Nearby ZIP codes are in USDA hardiness zones 4b to 5a.
- May 22Last spring frost (median)50% chance of 32°F after this date
- Jun 4Safer planting date10% chance of 32°F after this date
- Sep 27First fall frost (median)50% chance of 32°F by this date
- 126 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 21 | Jun 3 | Jun 25 |
| 32°F | May 7 | May 22 | Jun 4 |
| 28°F | Apr 26 | May 10 | May 25 |
| 24°F | Apr 14 | Apr 28 | May 15 |
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 | Aug 27 | Sep 13 | Sep 29 |
| 32°F | Sep 10 | Sep 27 | Oct 10 |
| 28°F | Sep 23 | Oct 7 | Oct 23 |
| 24°F | Oct 5 | Oct 22 | 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 | 72 days | 100 days | 121 days |
| 32°F | 106 days | 126 days | 146 days |
| 28°F | 127 days | 149 days | 171 days |
| 24°F | 150 days | 174 days | 196 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 |
|---|---|---|---|
| 49887 | 5a | -20 to -15°F | 2 km |
| 49848 | 5a | -20 to -15°F | 5 km |
| 49893 | 5a | -20 to -15°F | 13 km |
| 49821 | 5a | -20 to -15°F | 16 km |
| 54177 | 4b | -25 to -20°F | 17 km |
| 49812 | 5a | -20 to -15°F | 27 km |
| 49863 | 5a | -20 to -15°F | 27 km |
| 49847 | 5a | -20 to -15°F | 35 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 USC00207867, at 45.3903, -87.7025, elevation 210 m (690 ft).
- Data quality: Representative (10+ years), 14 years of freeze data.
- Average days per year at or below 32°F: 190.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Iron Mtn-Kingsford Wastewater Plant (53 km)
- Iron Mountain Ford Airport (57 km)
- Escanaba (60 km)
- Cornell 5se (64 km)
- Rapid River 4sse (79 km)
- Stambaugh 2sse (103 km)
- Garden Corners (106 km)
- Ki Sawyer Wastewater Plant (108 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.