Open dataset · CC-BY 4.0
USDA Zones & Frost Dates by US State — open table
| State | Abbr | Region | USDA zone range | Dominant zone | Avg last spring frost | Avg first fall frost | Coldest area | Warmest area |
|---|---|---|---|---|---|---|---|---|
| Alabama | AL | Southeast | 7a-9a | 8a | late March | early November | the northern Appalachian foothills (zone 7a) | the Gulf Coast around Mobile (zone 9a) |
| Alaska | AK | Pacific | 1a-8b | 4b | late May | mid-September | the interior near Fairbanks (zone 1a-2b) | the southeast coast and panhandle around Sitka (zone 8b) |
| Arizona | AZ | Southwest | 4b-10b | 9a | mid-February (low desert) | early December (low desert) | the high country around Flagstaff (zone 4b-6a) | the low desert around Yuma and Phoenix (zone 10b) |
| Arkansas | AR | Southeast | 6b-8a | 7b | early April | late October | the Ozark and Ouachita highlands (zone 6b) | the southern and Delta lowlands near Little Rock (zone 8a) |
| California | CA | Pacific | 5a-11a | 9b | mid-February (coast) to late April (interior) | mid-November (coast) to mid-October (interior) | the high Sierra Nevada (zone 5a-6a) | the southern coast and Imperial Valley (zone 11a) |
| Colorado | CO | West | 3b-7a | 5b | mid-May | late September | the high Rockies and mountain valleys (zone 3b-4b) | the western slope around Grand Junction (zone 7a) |
| Connecticut | CT | Northeast | 5b-7b | 6b | late April | mid-October | the northwest hills near Litchfield (zone 5b) | the Long Island Sound shoreline (zone 7b) |
| Delaware | DE | Northeast | 7a-8a | 7b | mid-April | late October | the northern Piedmont near Wilmington (zone 7a) | the Atlantic coast and lower Delmarva (zone 8a) |
| Florida | FL | Southeast | 8a-11b | 9b | late February (north) to no frost (south) | mid-December (north) to no frost (south) | the western Panhandle near Tallahassee (zone 8a) | the Florida Keys (zone 11b) |
| Georgia | GA | Southeast | 6b-9a | 8a | early April | early November | the Blue Ridge mountains in the north (zone 6b) | the Atlantic coast around Savannah (zone 9a) |
| Hawaii | HI | Pacific | 9a-13a | 12b | no frost | no frost | the upper slopes of Mauna Kea and Haleakala (zone 9a) | the coastal lowlands of all islands (zone 13a) |
| Idaho | ID | West | 3a-7a | 6a | mid-May | late September | the central mountains and high valleys (zone 3a-4b) | the Treasure Valley around Boise (zone 7a) |
| Illinois | IL | Midwest | 5a-7a | 6a | late April | mid-October | the northern counties near the Wisconsin line (zone 5a) | the far south near Cairo and Carbondale (zone 7a) |
| Indiana | IN | Midwest | 5b-7a | 6a | late April | mid-October | the northern lake-effect counties (zone 5b) | the Ohio River valley near Evansville (zone 7a) |
| Iowa | IA | Midwest | 4b-6a | 5b | late April | early October | the northern counties near Minnesota (zone 4b) | the southeast along the Mississippi (zone 6a) |
| Kansas | KS | Midwest | 5b-7a | 6b | mid-April | late October | the northwest High Plains (zone 5b) | the south-central plains around Wichita (zone 7a) |
| Kentucky | KY | Southeast | 6a-7b | 6b | mid-April | mid-October | the eastern Appalachian highlands (zone 6a) | the Ohio River valley around Louisville (zone 7b) |
| Louisiana | LA | Southeast | 8a-9b | 9a | mid-March | mid-November | the northern parishes near Shreveport (zone 8a) | the Gulf Coast and New Orleans (zone 9b) |
| Maine | ME | Northeast | 3b-6a | 5a | mid-May | late September | the far north Aroostook County interior (zone 3b) | the southern coast around Portland (zone 6a) |
| Maryland | MD | Northeast | 6a-8a | 7b | mid-April | late October | the western Appalachian panhandle near Oakland (zone 6a) | the Chesapeake and Atlantic shoreline (zone 8a) |
| Massachusetts | MA | Northeast | 5b-7b | 6b | late April | mid-October | the Berkshire hills in the west (zone 5b) | Cape Cod and the islands (zone 7b) |
| Michigan | MI | Midwest | 4a-6b | 6a | mid-May | early October | the western Upper Peninsula interior (zone 4a) | the southeast near Detroit and the Lake Michigan fruit belt (zone 6b) |
| Minnesota | MN | Midwest | 3a-5a | 4b | mid-May | late September | the far north near International Falls (zone 3a) | the Twin Cities metro and far south (zone 5a) |
| Mississippi | MS | Southeast | 7b-9a | 8b | late March | early November | the northern hill country near Tupelo (zone 7b) | the Gulf Coast around Gulfport (zone 9a) |
| Missouri | MO | Midwest | 5b-7a | 6b | mid-April | mid-October | the northern counties near Iowa (zone 5b) | the Bootheel in the southeast (zone 7a) |
| Montana | MT | West | 3a-6a | 4b | late May | mid-September | the high mountain valleys and northern plains (zone 3a) | the lower western valleys near Missoula (zone 6a) |
| Nebraska | NE | Midwest | 4b-6a | 5b | late April | early October | the northern Sandhills and Panhandle (zone 4b) | the southeast near the Missouri River (zone 6a) |
| Nevada | NV | Southwest | 4b-10a | 7a | mid-April | late October | the high northern Great Basin near Elko (zone 4b) | the Mojave around Las Vegas (zone 10a) |
| New Hampshire | NH | Northeast | 3b-6a | 5b | mid-May | late September | the White Mountains and far north (zone 3b) | the short Atlantic seacoast near Portsmouth (zone 6a) |
| New Jersey | NJ | Northeast | 6a-7b | 7a | mid-April | late October | the northwest Highlands near High Point (zone 6a) | the Atlantic shore and inner harbor (zone 7b) |
| New Mexico | NM | Southwest | 4b-9a | 7a | late April | late October | the high Sangre de Cristo mountains (zone 4b) | the southern Rio Grande and Chihuahuan desert (zone 9a) |
| New York | NY | Northeast | 3b-7b | 5b | early May (upstate) to mid-April (NYC) | early October (upstate) to early November (NYC) | the Adirondacks and Tug Hill plateau (zone 3b) | New York City and Long Island (zone 7b) |
| North Carolina | NC | Southeast | 5b-8b | 7b | early April | late October | the high Blue Ridge near Mount Mitchell (zone 5b) | the southern coast around Wilmington (zone 8b) |
| North Dakota | ND | Midwest | 3a-4b | 4a | mid-May | late September | the far north near the Canadian border (zone 3a) | the southern Red River and Missouri valleys (zone 4b) |
| Ohio | OH | Midwest | 5b-6b | 6a | late April | mid-October | the northeast snowbelt and Allegheny foothills (zone 5b) | the Ohio River valley near Cincinnati (zone 6b) |
| Oklahoma | OK | Southwest | 6b-8a | 7b | early April | late October | the Panhandle High Plains (zone 6b) | the south-central and southeast lowlands (zone 8a) |
| Oregon | OR | Pacific | 4b-9b | 8b | mid-April (Willamette Valley) | early November (Willamette Valley) | the high desert and Cascades east of the mountains (zone 4b) | the Willamette Valley and southwest interior (zone 9b) |
| Pennsylvania | PA | Northeast | 5a-7b | 6b | late April | mid-October | the northern Allegheny plateau (zone 5a) | the southeast around Philadelphia (zone 7b) |
| Rhode Island | RI | Northeast | 6a-7b | 7a | late April | mid-October | the northwest interior near Foster (zone 6a) | the Narragansett Bay shore and Newport (zone 7b) |
| South Carolina | SC | Southeast | 7a-9a | 8a | late March | early November | the Blue Ridge upstate near the mountains (zone 7a) | the Lowcountry coast around Charleston (zone 9a) |
| South Dakota | SD | Midwest | 3b-5a | 4b | mid-May | late September | the northern plains near North Dakota (zone 3b) | the southeast around Sioux Falls and the Black Hills foothills (zone 5a) |
| Tennessee | TN | Southeast | 6a-8a | 7a | mid-April | late October | the eastern Appalachian highlands (zone 6a) | the western Mississippi lowlands near Memphis (zone 8a) |
| Texas | TX | Southwest | 6a-10a | 8b | mid-March (most of state) | mid-November (most of state) | the northern Panhandle near Dalhart (zone 6a) | the lower Rio Grande Valley near Brownsville (zone 10a) |
| Utah | UT | West | 4a-9a | 6b | late April (Wasatch Front) | mid-October (Wasatch Front) | the high Uinta and central mountains (zone 4a) | the southwest Dixie around St. George (zone 9a) |
| Vermont | VT | Northeast | 3b-5b | 4b | mid-May | late September | the Green Mountains and Northeast Kingdom (zone 3b) | the Champlain Valley and southern river valleys (zone 5b) |
| Virginia | VA | Southeast | 5b-8a | 7b | mid-April | late October | the western Appalachian highlands (zone 5b) | the Tidewater and Hampton Roads coast (zone 8a) |
| Washington | WA | Pacific | 4a-9a | 8a | mid-April (Puget Sound) | early November (Puget Sound) | the Cascades and northeast highlands (zone 4a) | the Puget Sound lowland around Seattle (zone 9a) |
| Washington, DC | DC | Northeast | 7b-8a | 8a | mid-April | late October | outer neighborhoods away from the urban core (zone 7b) | the dense urban core, lifted by the city heat-island (zone 8a) |
| West Virginia | WV | Southeast | 5b-7a | 6b | late April | mid-October | the high Allegheny mountains near Davis (zone 5b) | the Ohio River valley near Huntington (zone 7a) |
| Wisconsin | WI | Midwest | 3b-6a | 5a | mid-May | early October | the north-central highlands near the UP line (zone 3b) | the Lake Michigan shore around Milwaukee (zone 6a) |
| Wyoming | WY | West | 3a-6a | 4b | late May | mid-September | the high mountain basins like Jackson Hole (zone 3a) | the lower southeast plains near Cheyenne (zone 6a) |
Methodology
Zone ranges and dominant half-zones are read from the USDA Plant Hardiness Zone Map 2023 revision. Frost dates are populated-area state averages derived from NOAA 1991–2020 climate normals; a single state can span several zones, so the coldest- and warmest-area columns flag that internal range. State-level figures are for orientation — local dates vary by ZIP code.
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:
US-state hardiness-zone and frost-date reference table compiled by Growli (getgrowli.app), CC-BY 4.0, from the USDA Plant Hardiness Zone Map (2023) and NOAA climate normals.
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