Washington County, Missouri
Local growing conditions for Washington County: the USDA hardiness zones found here, frost dates, and live weather for communities across the county. Based on 10 ZIP codes in our data.
Hardiness zones in Washington County
Washington County spans these USDA plant hardiness zones (by number of ZIP codes):
Local weather & frost dates
Open any community in Washington County for its live forecast, frost dates, and planting calendar:
Briarwood Estates 63030
Briarwood Estates 63071
Caledonia 63622
Summer Set 63626
Mineral Point 63630
Caledonia 63631
Irondale 63648
Mineral Point 63660
Potosi 63664
Summer Set 63674
More for Missouri
- Agriculture in Missouri
- Frost dates across Missouri
- 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.