Frost dates for Cass City 1 SSW, MI
At Cass City 1 SSW, the median last spring frost (32°F) is May 7 and the median first fall frost is Oct 10, for a typical growing season of 152 days. For a 90% chance that the last frost has passed, wait until May 22. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 7Last spring frost (median)50% chance of 32°F after this date
- May 22Safer planting date10% chance of 32°F after this date
- Oct 10First fall frost (median)50% chance of 32°F by this date
- 152 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 5 | May 19 | May 31 |
| 32°F | Apr 25 | May 7 | May 22 |
| 28°F | Apr 13 | Apr 28 | May 14 |
| 24°F | Mar 31 | Apr 15 | Apr 30 |
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 16 | Sep 30 | Oct 12 |
| 32°F | Sep 26 | Oct 10 | Oct 25 |
| 28°F | Oct 6 | Oct 24 | Nov 6 |
| 24°F | Oct 22 | Nov 5 | Nov 20 |
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 | 114 days | 131 days | 151 days |
| 32°F | 131 days | 152 days | 173 days |
| 28°F | 152 days | 176 days | 197 days |
| 24°F | 182 days | 203 days | 224 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 |
|---|---|---|---|
| 48726 | 6a | -10 to -5°F | 3 km |
| 48729 | 6a | -10 to -5°F | 10 km |
| 48735 | 6a | -10 to -5°F | 12 km |
| 48426 | 6a | -10 to -5°F | 13 km |
| 48754 | 6a | -10 to -5°F | 17 km |
| 48759 | 6a | -10 to -5°F | 23 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 USC00201361, at 43.5861, -83.1805, elevation 213 m (698 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 158.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Caro Wastewater Plant (20 km)
- Bad Axe (29 km)
- Sandusky (35 km)
- Filion 5nnw (37 km)
- Vassar (41 km)
- Harbor Beach 1 SSE (51 km)
- Frankenmuth 1se (52 km)
- Essexville (54 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.