Jefferson County, New York
Local growing conditions for Jefferson County: the USDA hardiness zones found here, frost dates, and live weather for communities across the county. Based on 38 ZIP codes in our data.
Hardiness zones in Jefferson County
Jefferson County spans these USDA plant hardiness zones (by number of ZIP codes):
Local weather & frost dates
Open any community in Jefferson County for its live forecast, frost dates, and planting calendar:
Watertown 13601
Fort Drum 13602
Fort Drum 13603
Adams 13605
Adams Center 13606
Alexandria Bay 13607
Oxbow 13608
Belleville 13611
Black River 13612
Brownville 13615
Calcium 13616
Cape Vincent 13618
Carthage 13619
Chaumont 13622
Clayton 13624
Deferiet 13628
Depauville 13632
Dexter 13634
Ellisburg 13636
Evans Mills 13637
Felts Mills 13638
Alexandria Bay 13640
Fishers Landing 13641
Great Bend 13643
More for New York
- Agriculture in New York
- Frost dates across New York
- 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.