Union County, New Jersey
Local growing conditions for Union County: the USDA hardiness zones found here, frost dates, and live weather for communities across the county. Based on 26 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:
Garwood 07027
Elizabeth 07201
Cranford 07016
Fanwood 07023
Kenilworth 07033
Linden 07036
Plainfield 07060
Plainfield 07062
Plainfield 07063
Rahway 07065
Rahway 07066
Fanwood 07076
Mountainside 07081
Union 07083
Vauxhall 07088
Westfield 07090
Mountainside 07092
Elizabeth 07202
Roselle 07203
Roselle Park 07204
Newark 07205
Elizabeth 07206
Elizabeth 07208
Summit 07901
More for New Jersey
- Agriculture in New Jersey
- Frost dates across New Jersey
- 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.