Clark County, Illinois
Local growing conditions for Clark County: the USDA hardiness zones found here, frost dates, and live weather for communities across the county. Based on 7 ZIP codes in our data.
Hardiness zones in Clark County
Clark County spans these USDA plant hardiness zones (by number of ZIP codes):
Local weather & frost dates
Open any community in Clark County for its live forecast, frost dates, and planting calendar:
Casey 62420
Marshall 62423
Marshall 62441
Martinsville 62442
Westfield 62474
West Union 62477
West York 62478
More for Illinois
- Agriculture in Illinois
- Frost dates across Illinois
- 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.