USDA plant hardiness zones
USDA plant hardiness zones divide the country by average annual extreme minimum winter temperature — the standard measure of which perennials survive an average winter. Hardiness sets winter survival; planting DATES depend on your local frost calendar, which can vary within a zone. Browse the 26 zones represented across 7,597 U.S. locations to see their temperature ranges and example places.
Hardiness zones across the U.S.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
What hardiness zones do — and don't — tell you
The USDA Plant Hardiness Zone Map divides North America into zones based on the average annual extreme minimum temperature — the coldest it typically gets in a winter. It is the standard guide to which perennials, shrubs, and trees will survive the winter in a given place, and it is what plant tags mean by "hardy to zone 5."
It does not tell you when to plant your tomatoes. Two towns in the same zone can have last-frost dates weeks apart, because winter lows and spring warm-up are different things. For planting timing, open a specific location and use its frost calendar; for winter survival of perennials, use the zone. See the crop guides for how each vegetable is timed, and the methodology for the data behind both.