Climate zones by state

Louisiana Climate Zones by Parish

Louisiana's 64 parishes span climate zones 2A to 3A under the 2021 International Energy Conservation Code (IECC). Zone 2A is the most common, with 37 of the 64. For reference, New Orleans and Baton Rouge are in zone 2A and Shreveport is in 3A.

Insulation minimums for each zone in Louisiana

ZoneParishesAtticWood-frame wallsFloors over unheated spaceBasement walls
2A37R-49R-13, or R-10ciR-13None required
3A27R-49R-20, or 13+5ci, or R-15ciR-19R-5ci or R-13

Minimums from the 2021 IECC (Table R402.1.3). Many areas still enforce an older edition, so check with your local building department. See sources.

Which energy code Louisiana uses

Louisiana enforces the 2021 IECC with amendments for homes (in effect since Jul 2023). Source: US Department of Energy, September 2026. Local governments can adopt newer codes or amendments. See every state's energy code.

What changed from the 2018 map

None of Louisiana's parishes changed zone between the 2018 and 2021 maps.

Every parish in Louisiana

NameZone (2021)Zone (2018)Details
Acadia Parish2A2AInsulation →
Allen Parish2A2AInsulation →
Ascension Parish2A2AInsulation →
Assumption Parish2A2AInsulation →
Avoyelles Parish2A2AInsulation →
Beauregard Parish2A2AInsulation →
Bienville Parish3A3AInsulation →
Bossier Parish3A3AInsulation →
Caddo Parish3A3AInsulation →
Calcasieu Parish2A2AInsulation →
Caldwell Parish3A3AInsulation →
Cameron Parish2A2AInsulation →
Catahoula Parish3A3AInsulation →
Claiborne Parish3A3AInsulation →
Concordia Parish3A3AInsulation →
De Soto Parish3A3AInsulation →
East Baton Rouge Parish2A2AInsulation →
East Carroll Parish3A3AInsulation →
East Feliciana Parish2A2AInsulation →
Evangeline Parish2A2AInsulation →
Franklin Parish3A3AInsulation →
Grant Parish3A3AInsulation →
Iberia Parish2A2AInsulation →
Iberville Parish2A2AInsulation →
Jackson Parish3A3AInsulation →
Jefferson Parish2A2AInsulation →
Jefferson Davis Parish2A2AInsulation →
La Salle Parish3A3AInsulation →
Lafayette Parish2A2AInsulation →
Lafourche Parish2A2AInsulation →
Lincoln Parish3A3AInsulation →
Livingston Parish2A2AInsulation →
Madison Parish3A3AInsulation →
Morehouse Parish3A3AInsulation →
Natchitoches Parish3A3AInsulation →
Orleans Parish2A2AInsulation →
Ouachita Parish3A3AInsulation →
Plaquemines Parish2A2AInsulation →
Pointe Coupee Parish2A2AInsulation →
Rapides Parish2A2AInsulation →
Red River Parish3A3AInsulation →
Richland Parish3A3AInsulation →
Sabine Parish3A3AInsulation →
St. Bernard Parish2A2AInsulation →
St. Charles Parish2A2AInsulation →
St. Helena Parish2A2AInsulation →
St. James Parish2A2AInsulation →
St. John the Baptist Parish2A2AInsulation →
St. Landry Parish2A2AInsulation →
St. Martin Parish2A2AInsulation →
St. Mary Parish2A2AInsulation →
St. Tammany Parish2A2AInsulation →
Tangipahoa Parish2A2AInsulation →
Tensas Parish3A3AInsulation →
Terrebonne Parish2A2AInsulation →
Union Parish3A3AInsulation →
Vermilion Parish2A2AInsulation →
Vernon Parish3A3AInsulation →
Washington Parish2A2AInsulation →
Webster Parish3A3AInsulation →
West Baton Rouge Parish2A2AInsulation →
West Carroll Parish3A3AInsulation →
West Feliciana Parish2A2AInsulation →
Winn Parish3A3AInsulation →

Source: Pacific Northwest National Laboratory, Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates (2022).

Frequently asked questions

What climate zone is Louisiana?

Louisiana spans IECC climate zones 2A to 3A; zone 2A is the most common. Find your parish in the table above, or search by ZIP code.

How much attic insulation do I need in Louisiana?

The 2021 IECC calls for R-49 in the attic everywhere in Louisiana.

What energy code does Louisiana use?

Louisiana enforces the 2021 IECC with amendments for homes (in effect since Jul 2023). Source: US Department of Energy, September 2026. Local governments can adopt newer codes or amendments.

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