IECC 2021 · PNNL
Arizona climate zones
Arizona’s 15 counties fall in 4 IECC 2021 climate zones: 2B (5), 3B (5), 4B (2), 5B (3).
Zone 2B: hot-dry
Attic target R49 (ENERGY STAR)La Paz County (Hot-dry) · Maricopa County (Hot-dry) · Pima County (Hot-dry) · Pinal County (Hot-dry) · Yuma County (Hot-dry)
Zone 3B: warm-dry
Attic target R49 (ENERGY STAR)Cochise County (Hot-dry) · Graham County (Hot-dry) · Greenlee County (Hot-dry) · Mohave County (Hot-dry) · Santa Cruz County (Hot-dry)
Zone 4B: mixed-dry
Attic target R60 (ENERGY STAR)Gila County (Mixed-dry) · Yavapai County (Mixed-dry)
Zone 5B: cool-dry
Attic target R60 (ENERGY STAR)Apache County (Cold) · Coconino County (Cold) · Navajo County (Cold)