Heating degree days
Sum over January to December of the degrees by which the daily mean temperature falls below 65°F, a measure of heating demand. NOAA estimates monthly values from nClimDiv temperatures and weights areas by population (2010 Census).
NOAA publishes these for operational monitoring; they can differ from official degree day publications.
Key facts
- Heating degree days in the United States was 4,062 degree days (base 65°F) in 2025, according to NOAA National Centers for Environmental Information.
- North Dakota had the highest heating degree days of 48 states in 2025, at 8,828 degree days (base 65°F), and Florida the lowest, at 614 degree days (base 65°F). Source: NOAA National Centers for Environmental Information.
- Published for 49 places, with figures from 1895 to 2025.
Rankings
US states by heating degree days, 2025
Places with data
Countries
Regions and states
- California
- Texas
- Florida
- New York
- Pennsylvania
- Illinois
- Ohio
- Georgia
- North Carolina
- Michigan
- Idaho
- Delaware
- Arkansas
- Arizona
- North Dakota
- Alabama
Use this data in your AI agent
Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:
Which places have the highest heating degree days? Use official data and cite it.
rank_places {"indicator":"heating_degree_days_annual","level":"region","within":"United States"}
GET https://invokely.ai/api/v1/rank?indicator=heating_degree_days_annual&level=region&within=United%20States