Though the landscape of the continental United States is vast, and the weather is sometimes unpredictable, classifying different areas by general trends in climate can be helpful to homeowners and builders alike. Almost two decades ago, the U.S. Department of Energy’s Building America Program came together with the International Code Council’s (ICC) International Energy Conservation Code (IECC) to define eight climate zones. The purpose was to “provide a simplified, consistent approach to defining climate for implementation of various codes”. These zones are “based on widely-accepted classifications of world climates that have been applied in a variety of different disciplines.” 1
Climate zones are defined to the county level and dictate some energy efficiency measures that are needed when building. Taken into account when designating a climate zone is: winter and summer average temperatures, humidity and rainfall, and heating degree days. (Heating degree days refer to an annual accumulation of heating demand.)
The ICC updates the IECC every three years. In 2021, for the first time since its inception, the Climate Zone map was changed, re-assigning 10% of counties in the US to a new Climate Zone. This trend reflects the general warming of the climate, as nearly all of the reassigned counties were shifted to a warmer Climate Zone.
The eight climate zones in the U.S. are defined as:
- Subarctic (appearing only in Alaska)
For a deeper explanation of each climate zone, and more corresponding maps, read more here.
What Climate Zone is your manufactured home community is located in? Find out by searching communities by zip code, every community profile on mhbo.com includes the climate zone the community is located in.
For an established homeowner, someone looking into buying in a new area, or a builder, getting acquainted with Climate Zones can help dictate what building features to seek, add, or steer clear of.