Frost dates for Owosso Wastewater Plant, MI
At Owosso Wastewater Plant, the median last spring frost (32°F) is May 1 and the median first fall frost is Oct 15, for a typical growing season of 164 days. For a 90% chance that the last frost has passed, wait until May 17. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 1Last spring frost (median)50% chance of 32°F after this date
- May 17Safer planting date10% chance of 32°F after this date
- Oct 15First fall frost (median)50% chance of 32°F by this date
- 164 daysGrowing season (median)between 32°F freezes
USDA hardiness zone 6a (-10 to -5°F) · see all zone 6a frost dates
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 28 | May 11 | May 28 |
| 32°F | Apr 17 | May 1 | May 17 |
| 28°F | Apr 5 | Apr 20 | May 5 |
| 24°F | Mar 25 | Apr 8 | 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 22 | Oct 4 | Oct 16 |
| 32°F | Oct 1 | Oct 15 | Oct 30 |
| 28°F | Oct 12 | Oct 28 | Nov 11 |
| 24°F | Oct 25 | Nov 8 | Nov 25 |
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 | 124 days | 144 days | 162 days |
| 32°F | 146 days | 164 days | 185 days |
| 28°F | 165 days | 188 days | 209 days |
| 24°F | 192 days | 214 days | 236 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 |
|---|---|---|---|
| 48867 | 6a | -10 to -5°F | 1 km |
| 48841 | 6a | -10 to -5°F | 12 km |
| 48649 | 6a | -10 to -5°F | 15 km |
| 48616 | 6a | -10 to -5°F | 20 km |
| 48848 | 6a | -10 to -5°F | 21 km |
| 48614 | 6a | -10 to -5°F | 28 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 USC00206300, at 43.0161, -84.1800, elevation 222 m (730 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 149.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Corunna 2 NE (9 km)
- Durand Wastewater Plant (18 km)
- Saint Johns (30 km)
- Flint 7W (33 km)
- Flint Bishop Intl Airport (35 km)
- Linden Wastewater Plant (38 km)
- Lansing Capital City Airport (42 km)
- East Lansing 4 S (45 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.