North Carolina Climate and Plant Hardiness Zones

North Carolina’s planting landscape is defined by a diverse range of USDA plant hardiness zones, which span from zone 6a to 9a according to the 2023 USDA planting map.

The state generally features a humid subtropical climate, although this classification does not apply to the Appalachian region.

Regional Temperature Variations

Temperature extremes vary significantly across the state’s geography. The northwestern portion of North Carolina experiences the coolest average extreme winter lows, with temperatures potentially dropping to -10 degrees Fahrenheit.

In contrast, the southeastern part of the state rarely experiences winter lows that fall to 20 degrees Fahrenheit.

USDA Map Updates and Climate Shifts

The 2023 USDA planting map reflects research conducted between 1991 and 2020, which led to changes in the growing zones across North Carolina. Most counties have seen their designations increase by a half zone.

As an example of this shift, Cabarrus County was designated as USDA zone 7b on the 2012 map, but the 2023 map indicates the county is now in zone 8.

These updates follow a steady rise in global annual temperatures since the 1960s.

Mapping and Planning Resources

The USDA provides several types of national and state maps to assist gardeners, including full zones and 2023-2012 difference maps. Half-zone maps are available, which include A/B subdivisions to provide more specific temperature ranges for a given location.

State and territory maps are available for download from the USDA in PNG format at resolutions of 150 or 300 dpi.

Understanding these zones is used to determine the best vegetables, fruits, flowers, and native plants for the coast, the Piedmont, and the mountains. Gardeners can identify their specific zone by entering their zip code on the United States Department of Agriculture website.