The 2021 International Energy Conservation Code (IECC) reveals warming climates in various counties across the United States, with the upper Midwest reporting the biggest warming changes. Major climate changes were also found in states like Wisconsin and Michigan, which are seeing higher temperatures compared to other regions which have stayed the same since the IECC’s 2018 report.
Though environmental changes like those shown on the 2021 IECC climate zone map affect everyone living in warming regions, a hotter climate also has serious implications for homeowners, builders, and manufacturers, says Energy Vanguard.
The big warming changes are in the upper Midwest. Wisconsin wins the award for the most change. It no longer has any counties in climate zone 7. The Upper Peninsula in Michigan also lost all of its CZ-7 counties but still has a toehold in that zone because one of the CZ-6 counties flipped to 7. Minnesota, which was about half CZ-6 and half CZ-7 now has some CZ-5 in the south and about a third of the state in CZ-7.
First, of course, these changes show that the climate really is changing. The folks who update the IECC are builders, code officials, manufacturers, and other stakeholders in the construction industry. Yes, there probably are some who talk about the “climate emergency,” but on the whole, I’d say this is a pretty conservative group. The IECC climate zones are based on actual numbers for heating and cooling degree days. This is a fact-based change.