Reference
USDA hardiness zones
USDA hardiness zones group regions by average annual minimum temperature in 5°F increments. Each numbered zone is split into "a" (colder half) and "b" (warmer half). Zones are the most reliable starting point for deciding what perennials and woody plants will survive winter in your area.
Cold to hot
Cold
zones 1a to 4b
Subarctic and far-north zones. Hard winters, very short summers, only the toughest perennials and cold-hardy fruit varieties.
- -60°F to -55°F · 50-day seasonNorthern Alaska interior
- -55°F to -50°F · 60-day seasonFar-north Alaska interior
- -50°F to -45°F · 70-day seasonInterior Alaska · Northern Canada border areas
- -45°F to -40°F · 80-day seasonAlaska interior · Far northern Minnesota
- -40°F to -35°F · 90-day seasonInterior Alaska · Northern Minnesota
- -35°F to -30°F · 100-day seasonNorthern Maine · Upper Michigan
- -30°F to -25°F · 120-day seasonNorthern Vermont · Northern Wisconsin
- -25°F to -20°F · 130-day seasonCentral Vermont · Northern Iowa
Cool temperate
zones 5a to 7b
The classic apple, pear, and stone-fruit belt. Cold winters meet long enough summers for most home orchard species.
- -20°F to -15°F · 150-day seasonMaine · Western New York
- -15°F to -10°F · 165-day seasonSouthern Vermont · Central Ohio
- -10°F to -5°F · 180-day seasonNorthern New Jersey · Central Missouri
- -5°F to 0°F · 190-day seasonLong Island · Southern Indiana
- 0°F to 5°F · 210-day seasonNorthern Virginia · Northern North Carolina
- 5°F to 10°F · 220-day seasonCentral North Carolina (Chapel Hill, Raleigh) · Northern Georgia
Warm temperate
zones 8a to 10b
Mild winters, long growing seasons. Low chill hours mean variety selection becomes the limiting factor for tree fruit.
- 10°F to 15°F · 240-day seasonSouthern Georgia · Central Texas
- 15°F to 20°F · 260-day seasonNorthern Florida · Coastal Texas
- 20°F to 25°F · 290-day seasonCentral Florida · Coastal California
- 25°F to 30°F · 310-day seasonSouthern Florida (north) · Houston, TX
- 30°F to 35°F · 340-day seasonSouth Florida · Coastal Southern California
- 35°F to 40°F · 365-day seasonMiami, FL · Florida Keys
Subtropical
zones 11a to 13b
Frost-free or near frost-free year-round. Tropical fruit thrives; cold-requiring crops largely don't.
- 40°F to 45°F · 365-day seasonLower Florida Keys · Hawaii (lower elevations)
- 45°F to 50°F · 365-day seasonCoastal Hawaii · Southernmost Florida Keys
- 50°F to 55°F · 365-day seasonHawaii lowlands · Puerto Rico coastal areas
- 55°F to 60°F · 365-day seasonHawaii Big Island leeward · Puerto Rico interior
- 60°F to 65°F · 365-day seasonLowest-elevation Hawaii · Hottest Puerto Rico locations
- 65°F to 70°F · 365-day seasonSea-level Hawaii leeward · Puerto Rico's hottest valleys