# 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).

## 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.
- Figures last updated on 2026-10-12.

- Indicator id: `heating_degree_days_annual`
- Unit: degree days (base 65°F)
- Note: NOAA publishes these for operational monitoring; they can differ from official degree day publications.
- Web page: https://invokely.ai/en/heating-degree-days
- API: https://invokely.ai/api/v1/indicators/heating_degree_days_annual

## Latest figures

| Place | Period | degree days (base 65°F) | Source |
|---|---|---:|---|
| United States | 2025 | 4,062 | NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December heating degree days (base 65°F), contiguous US and statewide. From the NOAA Monthly U.S. Climate Divisional Database (nClimDiv), doi:10.7289/V5M32STR. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/national/time-series/110/hdd/12/12/1895-2026/data.json. Retrieved 2026-10-12. |

## Rankings

- [US states](https://invokely.ai/rankings/heating-degree-days/us-states.md) (48 places)