IECC 2021 · PNNL
Connecticut climate zones
Connecticut’s 9 counties fall in 1 IECC 2021 climate zone: 5A (9).
Zone 5A: cool-humid
Attic target R60 (ENERGY STAR)Capitol Planning Region (Cold) · Greater Bridgeport Planning Region (Cold) · Lower Connecticut River Valley Planning Region (Cold) · Naugatuck Valley Planning Region (Cold) · Northeastern Connecticut Planning Region (Cold) · Northwest Hills Planning Region (Cold) · South Central Connecticut Planning Region (Cold) · Southeastern Connecticut Planning Region (Cold) · Western Connecticut Planning Region (Cold)