Union County, Pennsylvania
Local growing conditions for Union County: the USDA hardiness zones found here, frost dates, and live weather for communities across the county. Based on 11 ZIP codes in our data.
Hardiness zones in Union County
Union County spans these USDA plant hardiness zones (by number of ZIP codes):
Local weather & frost dates
Open any community in Union County for its live forecast, frost dates, and planting calendar:
Hartleton 17829
Laurelton 17835
Lewisburg 17837
Mifflinburg 17844
Laurelton 17845
New Berlin 17855
New Columbia 17856
Hartleton 17880
Woodward 17885
West Milton 17886
Watsontown 17887
More for Pennsylvania
- Agriculture in Pennsylvania
- Frost dates across Pennsylvania
- USDA hardiness zones explained
- Planting calendar by ZIP code
← All counties in Pennsylvania
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.