USDA Hardiness Zone 4a

1 town pages in this zone so far.

Zone 4a on the 2023 USDA Plant Hardiness Zone Map means an average annual extreme minimum temperature of -30°F to -25°F, averaged over 1991 to 2020. The zone is about the coldest winter night, not frost dates or summer heat, so towns in the same zone can have different frost dates.

Towns in zone 4a

BismarckZone 4a, median last frost May 14

Source: USDA Plant Hardiness Zone Map 2023, USDA-ARS and PRISM Group, Oregon State University. Zone of each town at its center point.