Louisiana climate

Louisiana Plant Hardiness Zones

Louisiana’s towns run from zone 8b to zone 10a: the average coldest winter night is 33.6°F at Grand Isle and 16.2°F at Junction City.

Hardiness zones in Louisiana

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 Louisiana, from zone 8b to zone 10a, with the state’s border drawn.
  • 8b
  • 9a
  • 9b
  • 10a

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.

10a Zone 10a, 30 to 35°F 4 towns

9b Zone 9b, 25 to 30°F 99 towns

9a Zone 9a, 20 to 25°F 189 towns

8b Zone 8b, 15 to 20°F 83 towns

Counties

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

CountyZone at the centerAverage coldest night
Acadia Parish9a23.7°F
Allen Parish9a22.6°F
Ascension Parish9a23.8°F
Assumption Parish9b25.6°F
Avoyelles Parish9a21.6°F
Beauregard Parish9a22.4°F
Bienville Parish8b17°F
Bossier Parish8b18.4°F
Caddo Parish8b18.7°F
Calcasieu Parish9b25°F
Caldwell Parish8b18.9°F
Cameron Parish9b26.7°F
Catahoula Parish9a20.1°F
Claiborne Parish8b16.4°F
Concordia Parish9a20.6°F
De Soto Parish8b19.5°F
East Baton Rouge Parish9a22.6°F
East Carroll Parish8b19.2°F
East Feliciana Parish9a20.8°F
Evangeline Parish9a22.4°F
Franklin Parish8b19.5°F
Grant Parish9a20.3°F
Iberia Parish9b27.8°F
Iberville Parish9a23.7°F
Jackson Parish8b17.5°F
Jefferson Davis Parish9a24.5°F
Jefferson Parish9b27.3°F
Lafayette Parish9a23.7°F
Lafourche Parish9b26.5°F
LaSalle Parish8b18.2°F
Lincoln Parish8b17.9°F
Livingston Parish9a21.8°F
Madison Parish8b19.3°F
Morehouse Parish8b17.9°F
Natchitoches Parish9a20.7°F
Orleans Parish9b29.3°F
Ouachita Parish8b18.8°F
Plaquemines Parish9b28.5°F
Pointe Coupee Parish9a22.8°F
Rapides Parish9a20.9°F
Red River Parish8b19°F
Richland Parish8b19.7°F
Sabine Parish8b19.7°F
Saint Bernard Parish9b28.4°F
Saint Charles Parish9b27.1°F
Saint Helena Parish9a20°F
Saint James Parish9b25°F
Saint John the Baptist Parish9b26.9°F
Saint Landry Parish9a23°F
Saint Martin Parish9a24.4°F
Saint Tammany Parish9a22.6°F
St. Mary Parish9b26.5°F
Tangipahoa Parish9a20.4°F
Tensas Parish8b19.5°F
Terrebonne Parish9b26.7°F
Union Parish8b17.8°F
Vermilion Parish9b25.2°F
Vernon Parish9a21.1°F
Washington Parish9a20.3°F
Webster Parish8b17.4°F
West Baton Rouge Parish9a22.9°F
West Carroll Parish8b18.4°F
West Feliciana Parish9a21.7°F
Winn Parish8b19.4°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
8b15 to 20°F-9.4 to -6.7°C
9a20 to 25°F-6.7 to -3.9°C
9b25 to 30°F-3.9 to -1.1°C
10a30 to 35°F-1.1 to 1.7°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.