Boulder County, Colorado
Local growing conditions for Boulder County: the USDA hardiness zones found here, frost dates, and live weather for communities across the county. Based on 18 ZIP codes in our data.
Hardiness zones in Boulder County
Boulder County spans these USDA plant hardiness zones (by number of ZIP codes):
Local weather & frost dates
Open any community in Boulder County for its live forecast, frost dates, and planting calendar:
Boulder 80310
Longmont 80501
Eldorado Springs 80025
Erie 80026
Superior 80027
Gunbarrel 80301
Tall Timber 80302
Boulder 80303
Boulder 80304
Boulder 80305
Glendale 80455
Nederland 80466
Coal Creek 80471
Ward 80481
Longmont 80503
Allenspark 80510
Allenspark 80540
Niwot 80544
More for Colorado
- Agriculture in Colorado
- Frost dates across Colorado
- 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.