Climate zones by state

Mississippi Climate Zones by County

Mississippi's 82 counties span climate zones 2A to 3A under the 2021 International Energy Conservation Code (IECC). Zone 3A is the most common, with 76 of the 82. For reference, Gulfport is in zone 2A and Jackson and Tupelo are in 3A.

Insulation minimums for each zone in Mississippi

ZoneCountiesAtticWood-frame wallsFloors over unheated spaceBasement walls
2A6R-49R-13, or R-10ciR-13None required
3A76R-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 Mississippi uses

Mississippi has no statewide residential energy code; cities and counties adopt their own, so check with your local building department. 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

One county moved one zone warmer in the 2021 map: George County (3 → 2). If your town still enforces the 2018 or 2015 code, the older zone applies to permits.

Every county in Mississippi

NameZone (2021)Zone (2018)Details
Adams County3A3AInsulation →
Alcorn County3A3AInsulation →
Amite County3A3AInsulation →
Attala County3A3AInsulation →
Benton County3A3AInsulation →
Bolivar County3A3AInsulation →
Calhoun County3A3AInsulation →
Carroll County3A3AInsulation →
Chickasaw County3A3AInsulation →
Choctaw County3A3AInsulation →
Claiborne County3A3AInsulation →
Clarke County3A3AInsulation →
Clay County3A3AInsulation →
Coahoma County3A3AInsulation →
Copiah County3A3AInsulation →
Covington County3A3AInsulation →
DeSoto County3A3AInsulation →
Forrest County3A3AInsulation →
Franklin County3A3AInsulation →
George County2A3A changedInsulation →
Greene County3A3AInsulation →
Grenada County3A3AInsulation →
Hancock County2A2AInsulation →
Harrison County2A2AInsulation →
Hinds County3A3AInsulation →
Holmes County3A3AInsulation →
Humphreys County3A3AInsulation →
Issaquena County3A3AInsulation →
Itawamba County3A3AInsulation →
Jackson County2A2AInsulation →
Jasper County3A3AInsulation →
Jefferson County3A3AInsulation →
Jefferson Davis County3A3AInsulation →
Jones County3A3AInsulation →
Kemper County3A3AInsulation →
Lafayette County3A3AInsulation →
Lamar County3A3AInsulation →
Lauderdale County3A3AInsulation →
Lawrence County3A3AInsulation →
Leake County3A3AInsulation →
Lee County3A3AInsulation →
Leflore County3A3AInsulation →
Lincoln County3A3AInsulation →
Lowndes County3A3AInsulation →
Madison County3A3AInsulation →
Marion County3A3AInsulation →
Marshall County3A3AInsulation →
Monroe County3A3AInsulation →
Montgomery County3A3AInsulation →
Neshoba County3A3AInsulation →
Newton County3A3AInsulation →
Noxubee County3A3AInsulation →
Oktibbeha County3A3AInsulation →
Panola County3A3AInsulation →
Pearl River County2A2AInsulation →
Perry County3A3AInsulation →
Pike County3A3AInsulation →
Pontotoc County3A3AInsulation →
Prentiss County3A3AInsulation →
Quitman County3A3AInsulation →
Rankin County3A3AInsulation →
Scott County3A3AInsulation →
Sharkey County3A3AInsulation →
Simpson County3A3AInsulation →
Smith County3A3AInsulation →
Stone County2A2AInsulation →
Sunflower County3A3AInsulation →
Tallahatchie County3A3AInsulation →
Tate County3A3AInsulation →
Tippah County3A3AInsulation →
Tishomingo County3A3AInsulation →
Tunica County3A3AInsulation →
Union County3A3AInsulation →
Walthall County3A3AInsulation →
Warren County3A3AInsulation →
Washington County3A3AInsulation →
Wayne County3A3AInsulation →
Webster County3A3AInsulation →
Wilkinson County3A3AInsulation →
Winston County3A3AInsulation →
Yalobusha County3A3AInsulation →
Yazoo County3A3AInsulation →

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 Mississippi?

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

How much attic insulation do I need in Mississippi?

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

What energy code does Mississippi use?

Mississippi has no statewide residential energy code; cities and counties adopt their own, so check with your local building department. Source: US Department of Energy, September 2026. Local governments can adopt newer codes or amendments.

More for Mississippi: Last frost dates in Mississippi · Mississippi planting zones · Frost line depth by state