Frost dates for Caro Wastewater Plant, MI
At Caro Wastewater Plant, the median last spring frost (32°F) is May 7 and the median first fall frost is Oct 9, for a typical growing season of 154 days. For a 90% chance that the last frost has passed, wait until May 24. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 7Last spring frost (median)50% chance of 32°F after this date
- May 24Safer planting date10% chance of 32°F after this date
- Oct 9First fall frost (median)50% chance of 32°F by this date
- 154 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 4 | May 20 | Jun 4 |
| 32°F | Apr 24 | May 7 | May 24 |
| 28°F | Apr 12 | Apr 27 | May 15 |
| 24°F | Mar 31 | Apr 14 | Apr 29 |
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 15 | Oct 1 | Oct 13 |
| 32°F | Sep 25 | Oct 9 | Oct 26 |
| 28°F | Oct 4 | Oct 23 | Nov 7 |
| 24°F | Oct 19 | Nov 5 | Nov 21 |
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 | 111 days | 132 days | 154 days |
| 32°F | 133 days | 154 days | 175 days |
| 28°F | 154 days | 179 days | 199 days |
| 24°F | 181 days | 202 days | 226 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 |
|---|---|---|---|
| 48723 | 6a | -10 to -5°F | 1 km |
| 48744 | 6a | -10 to -5°F | 15 km |
| 48733 | 6a | -10 to -5°F | 17 km |
| 48701 | 6a | -10 to -5°F | 18 km |
| 48741 | 6a | -10 to -5°F | 19 km |
| 48767 | 6a | -10 to -5°F | 19 km |
| 48760 | 6a | -10 to -5°F | 22 km |
| 48727 | 6a | -10 to -5°F | 26 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 USC00201299, at 43.4839, -83.3919, elevation 210 m (690 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 152.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Vassar (20 km)
- Cass City 1 SSW (20 km)
- Frankenmuth 1se (32 km)
- Essexville (39 km)
- Saginaw #3 (46 km)
- Sandusky (47 km)
- Lapeer 2w (47 km)
- Lapeer Wastewater Plant (48 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.