St. Clair County, Michigan
Local growing conditions for St. Clair County: the USDA hardiness zones found here, frost dates, and live weather for communities across the county. Based on 21 ZIP codes in our data.
Hardiness zones in St. Clair County
St. Clair County spans these USDA plant hardiness zones (by number of ZIP codes):
Local weather & frost dates
Open any community in St. Clair County for its live forecast, frost dates, and planting calendar:
Pearl Beach 48001
Capac 48002
Ruby 48006
Capac 48014
Emmett 48022
New Baltimore 48023
Emmett 48027
Pearl Beach 48028
Lakeport 48032
Marine City 48039
Marysville 48040
Memphis 48041
Ruby 48049
St. Clair 48054
Lakeport 48059
Port Huron 48060
Richmond 48063
Richmond 48064
Marysville 48074
St. Clair 48079
Yale 48097
More for Michigan
- Agriculture in Michigan
- Frost dates across Michigan
- USDA hardiness zones explained
- Planting calendar by ZIP code
County growing conditions are compiled from our ZIP-code database, USDA hardiness-zone data, and NOAA climate normals. Conditions vary within a county by elevation and local microclimate. Page updated Aug 4, 2026.