Open dataset · CC-BY 4.0
USDA Plant Hardiness Zones — full reference table (1–13)
| Zone | Avg min temp (°F) | Avg min temp (°C) | Avg last spring frost | Avg first fall frost | Growing days | Representative US regions | What thrives here |
|---|---|---|---|---|---|---|---|
| 1 | -60 to -50°F | -51 to -46°C | mid-June | mid-August | 60 | Interior Alaska (Fairbanks region) | Sub-arctic. Only the hardiest cold-tolerant crops and trees survive. |
| 2 | -50 to -40°F | -46 to -40°C | early June | late August | 90 | Northern Alaska, parts of northern Canada | Very short season. Cold-hardy vegetables and shrubs only. |
| 3 | -40 to -30°F | -40 to -34°C | late May | early September | 110 | Northern Minnesota, North Dakota, interior Alaska | Cold-hardy fruit trees plus most cool-season vegetables. |
| 4 | -30 to -20°F | -34 to -29°C | mid-May | mid-September | 125 | Northern Maine, northern Wisconsin, Montana, parts of New England | Cold-climate gardening. Most vegetables, many fruit trees, hardy ornamentals. |
| 5 | -20 to -10°F | -29 to -23°C | late April / early May | late September / early October | 150 | Iowa, southern Wisconsin, northern Illinois, parts of New York | Productive Midwest gardening. Wide vegetable selection, robust fruit production. |
| 6 | -10 to 0°F | -23 to -18°C | mid- to late April | mid- to late October | 180 | Southern Pennsylvania, Ohio, Missouri, parts of mid-Atlantic | Long-season productive zone. Almost every common vegetable and most fruits. |
| 7 | 0 to 10°F | -18 to -12°C | mid-April | late October / early November | 200 | Virginia, North Carolina (mountains), Oklahoma, Tennessee | Long warm season + mild winters. Wide crop selection including figs and pomegranates. |
| 8 | 10 to 20°F | -12 to -7°C | mid- to late March | mid-November | 230 | Texas (much of), Louisiana, North Florida, Oregon coast, Washington (parts) | Mild winters, hot summers. Subtropical possibilities mixed with temperate. |
| 9 | 20 to 30°F | -7 to -1°C | mid-February to early March | late November / early December | 280 | Central + South Florida, Southern Texas, Southern California, Arizona | Subtropical. Year-round growing for most crops. Frost is rare and brief. |
| 10 | 30 to 40°F | -1 to 4°C | frost rare or never | frost rare or never | 365 | South Florida, Coastal Southern California, Hawaii (parts) | Tropical. Year-round growing. True frost-free climate. |
| 11 | 40 to 50°F | 4 to 10°C | no frost | no frost | 365 | Florida Keys, Hawaii (most), Puerto Rico, southern California (coastal) | Frost-free tropical. Year-round all crops except those needing cold dormancy. |
| 12 | 50 to 60°F | 10 to 16°C | no frost | no frost | 365 | Hawaii (lowland), Puerto Rico (parts) | Tropical lowland. Heat-adapted plants only. |
| 13 | 60 to 70°F | 16 to 21°C | no frost | no frost | 365 | Hawaii (coastal lowlands), Puerto Rico (south coast) | Hot tropical. Strictly tropical species. |
Methodology
Temperature bands are the published USDA Plant Hardiness Zone Map (2023 revision) 10 °F zone definitions. Frost-date and growing-season figures are mid-zone US national averages derived from NOAA Climate Data Online normals; local dates vary by ZIP code. Region and signature-planting columns are editorial summaries for orientation, not climate measurements.
Sources
- USDA Plant Hardiness Zone Map, 2023 revision (planthardiness.ars.usda.gov)
- NOAA Climate Data Online — 1991–2020 climate normals (ncei.noaa.gov)
Last verified 2026-05-15.
License & citation
This dataset is published under Creative Commons Attribution 4.0. You may reuse it commercially or non-commercially with credit. Suggested attribution:
USDA hardiness-zone reference table compiled by Growli (getgrowli.app), CC-BY 4.0, from the USDA Plant Hardiness Zone Map (2023) and NOAA climate normals.
Want this applied to your actual garden?
A table tells you the rule. The Growli app tells you what to do — it knows your plants, your zone, and your local weather, and turns reference data like this into daily watering, frost, and repot reminders.