Vermont climate

Vermont Plant Hardiness Zones

Vermont’s towns run from zone 4a to zone 6a: the average coldest winter night is -9.6°F at Brattleboro and -28.1°F at Island Pond.

Hardiness zones in Vermont

In USDA’s colors, neighboring states washed out. Zones follow elevation, coasts and cities down to half a mile. Drawn by WeatherOverTime from the USDA-ARS and Oregon State University PRISM Climate Group 2023 GIS data; this is not the official USDA Plant Hardiness Zone Map.

Map of the 2023 plant hardiness zones across Vermont, from zone 4a to zone 6a, with the state’s border drawn.
  • 4a
  • 4b
  • 5a
  • 5b
  • 6a

Open the live map with plant hardiness zones

Towns by zone

Each town’s 1991-2020 average annual extreme minimum at its center, read from the map’s 800 m grid. Warmest zone first.

6a Zone 6a, -10 to -5°F 1 towns

5b Zone 5b, -15 to -10°F 24 towns

5a Zone 5a, -20 to -15°F 60 towns

4b Zone 4b, -25 to -20°F 28 towns

4a Zone 4a, -30 to -25°F 4 towns

Counties

At the county’s center; a county with hills or a coast spans several zones.

CountyZone at the centerAverage coldest night
Addison County5a-17.1°F
Bennington County5a-15.3°F
Caledonia County4b-22.9°F
Chittenden County5a-18.3°F
Essex County4b-24.2°F
Franklin County4b-20.4°F
Grand Isle County5a-17.1°F
Lamoille County4b-22.7°F
Orange County5a-17.8°F
Orleans County4b-24.5°F
Rutland County5a-15.9°F
Washington County5a-19.7°F
Windham County5b-12.4°F
Windsor County5b-14.6°F

The zones

A plant hardiness zone is set by the average of each winter’s single coldest temperature, 1991 to 2020: zones are 10°F apart and each half zone, a and b, 5°F. It says how cold a winter night usually gets, not the coldest it has ever been, and nothing about summer heat, rain or soil. Plant labels give the coldest zone a perennial survives in.

ZoneAverage coldest nightIn Celsius
4a-30 to -25°F-34.4 to -31.7°C
4b-25 to -20°F-31.7 to -28.9°C
5a-20 to -15°F-28.9 to -26.1°C
5b-15 to -10°F-26.1 to -23.3°C
6a-10 to -5°F-23.3 to -20.6°C

Sources

Hardiness zones: USDA Plant Hardiness Zone Map, 2023, Agricultural Research Service, U.S. Department of Agriculture, from the GIS data of the PRISM Climate Group, Oregon State University, which may be freely reproduced and redistributed. Drawn by WeatherOverTime from the USDA-ARS and Oregon State University PRISM Climate Group 2023 GIS data; this is not the official USDA Plant Hardiness Zone Map.