Maine has 8 USDA hardiness zones from 3b to 7a, with average winter lows from -35°F at Aroostook County’s Clayton Lake area to 5°F along York and Cumberland Counties’ southern coast, per the 2023 USDA Plant Hardiness Zone Map.
The cold north covers Aroostook (3b–5a), Piscataquis (4a–5a), Somerset, Oxford, Franklin, and Penobscot Counties (4a–5b), with Bangor at zone 5a in Penobscot County. Northwestern Allagash highlands include Maine’s coldest pockets at zone 3b in Aroostook County.
Coastal Cumberland, Hancock, Knox, Lincoln, and Sagadahoc Counties warm to zones 5b–6b, with Portland at zones 5b–6b in Cumberland County. Yarmouth at zone 6a, Woolwich at zones 5b–6a, and York County’s southernmost coast extend to zone 7a — Maine’s warmest USDA classification.
Maine’s hardiness zones are also called planting zones, growing zones, plant zones, USDA zones, climate zones, or gardening zones.
Use the city, town, and county lists below, search by ZIP code, or open the interactive Maine planting zones map for precise USDA zone locations.
Maine Planting Zones by ZIP Code
Maine Planting Zones Map
Planting Zones
Planting Zones
USDA Hardiness Zones for Maine Counties
| Maine Counties | Hardiness Zones |
|---|---|
| Androscoggin County | Zone 5a and 5b |
| Aroostook County | Zone 3b, 4a, 4b and 5a |
| Cumberland County | Zone 5a, 5b, 6a and 6b |
| Franklin County | Zone 4a, 4b, 5a and 5b |
| Hancock County | Zone 5a, 5b, 6a and 6b |
| Kennebec County | Zone 5a and 5b |
| Knox County | Zone 5b, 6a, 6b and 7a |
| Lincoln County | Zone 5b, 6a, 6b and 7a |
| Oxford County | Zone 4a, 4b, 5a and 5b |
| Penobscot County | Zone 4a, 4b, 5a and 5b |
| Piscataquis County | Zone 3b, 4a, 4b and 5a |
| Sagadahoc County | Zone 5b, 6a and 6b |
| Somerset County | Zone 3b, 4a, 4b, 5a and 5b |
| Waldo County | Zone 5a, 5b and 6a |
| Washington County | Zone 4b, 5a, 5b, 6a and 6b |
USDA Hardiness Zones for Maine Cities and Towns
| Maine Cities/Towns | Hardiness Zones |
|---|---|
| Alfred | Zone 5b |
| Anson | Zone 5a |
| Ashland | Zone 4a |
| Auburn | Zone 5b |
| Augusta | Zone 5b |
| Bangor | Zone 5a |
| Bar Harbor | Zone 6a |
| Bath | Zone 5b and 6a |
| Belfast | Zone 5a and 5b |
| Berwick | Zone 6a |
| Biddeford | Zone 5b and 6a |
| Bingham | Zone 5a |
| Blaine | Zone 4a |
| Blue Hill | Zone 5b |
| Boothbay Harbor | Zone 6a |
| Bowdoinham | Zone 5b |
| Brewer | Zone 5a |
| Bridgton | Zone 5a and 5b |
| Brunswick | Zone 5b and 6a |
| Bucksport | Zone 5a and 5b |
| Calais | Zone 5a and 5b |
| Cape Neddick | Zone 6a |
| Caribou | Zone 4a and 4b |
| Casco | Zone 5b |
| Castine | Zone 5b |
| Chisholm | Zone 5a |
| Clinton | Zone 5a and 5b |
| Cousins Island | Zone 6a |
| Cumberland Center | Zone 5b and 6a |
| Damariscotta | Zone 5b and 6a |
| Dexter | Zone 4b and 5a |
| Dixfield | Zone 5a and 5b |
| Dover-Foxcroft | Zone 4b and 5a |
| Eagle Lake | Zone 4a |
| East Millinocket | Zone 5a |
| Eastport | Zone 6a |
| Ellsworth | Zone 5a and 5b |
| Fairfield | Zone 5a and 5b |
| Falmouth | Zone 6a |
| Falmouth Foreside | Zone 6a |
| Farmingdale | Zone 5b |
| Farmington | Zone 5a |
| Fort Fairfield | Zone 4a |
| Freeport | Zone 6a |
| Fryeburg | Zone 5a |
| Gardiner | Zone 5b |
| Gorham | Zone 5b |
| Gray | Zone 5b |
| Greenville | Zone 4b and 5a |
| Guilford | Zone 5a |
| Hallowell | Zone 5b |
| Hampden | Zone 5a |
| Hartland | Zone 4b and 5a |
| Houlton | Zone 4b |
| Howland | Zone 5a |
| Kennebunk | Zone 5b and 6a |
| Kennebunkport | Zone 6a |
| Kittery | Zone 6a |
| Kittery Point | Zone 6a |
| Lake Arrowhead | Zone 5a and 5b |
| Lewiston | Zone 5b |
| Limestone | Zone 4a |
| Lisbon Falls | Zone 5b |
| Little Falls | Zone 5b |
| Littlejohn Island | Zone 6a |
| Livermore Falls | Zone 5a |
| Lubec | Zone 6a |
| Machias | Zone 5b |
| Madawaska | Zone 4a and 4b |
| Madison | Zone 5a |
| Mapleton | Zone 4a |
| Mars Hill | Zone 4a |
| Mechanic Falls | Zone 5b |
| Mexico | Zone 5a and 5b |
| Milford | Zone 5a |
| Millinocket | Zone 5a |
| Milo | Zone 5a |
| Naples | Zone 5a and 5b |
| Newcastle | Zone 5b and 6a |
| Newport | Zone 4b and 5a |
| Norridgewock | Zone 5a |
| North Berwick | Zone 5b and 6a |
| North Windham | Zone 5b |
| Norway | Zone 5a and 5b |
| Old Orchard Beach | Zone 6a and 6b |
| Old Town | Zone 5a and 5b |
| Orono | Zone 5a and 5b |
| Oxford | Zone 5a and 5b |
| Pittsfield | Zone 5a |
| Portland | Zone 5b, 6a and 6b |
| Presque Isle | Zone 4a and 4b |
| Randolph | Zone 5b |
| Richmond | Zone 5b |
| Rockland | Zone 5b and 6a |
| Rumford | Zone 5a and 5b |
| Saco | Zone 5b, 6a and 6b |
| Sanford | Zone 5b |
| Searsport | Zone 5b |
| Skowhegan | Zone 5a |
| South Eliot | Zone 6a |
| South Paris | Zone 5a and 5b |
| South Windham | Zone 5b |
| Southwest Harbor | Zone 6a |
| Standish | Zone 5a and 5b |
| Steep Falls | Zone 5a and 5b |
| Thomaston | Zone 6a |
| Topsham | Zone 5b |
| Unity | Zone 5a |
| Van Buren | Zone 3b and 4a |
| Waldoboro | Zone 5b and 6a |
| Washburn | Zone 4a |
| Waterville | Zone 5b |
| West Kennebunk | Zone 5b |
| Westbrook | Zone 5b and 6a |
| Wilton | Zone 5a |
| Winslow | Zone 5b |
| Winter Harbor | Zone 6a |
| Winterport | Zone 5a and 5b |
| Winthrop | Zone 5b |
| Wiscasset | Zone 5b |
| Woodland | Zone 5a and 5b |
| Woolwich | Zone 5b and 6a |
| Yarmouth | Zone 6a |
| York Harbor | Zone 6a |