# Heating degree days in Delaware

Heating degree days in Delaware was 4,547 degree days (base 65°F) in 2025. Source: NOAA National Centers for Environmental Information.

- Indicator id: `heating_degree_days_annual`
- Place id: `us-state-10`
- Unit: degree days (base 65°F)
- Definition: 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).
- Note: NOAA publishes these for operational monitoring; they can differ from official degree day publications.
- Source: NOAA National Centers for Environmental Information, NOAA Climate at a Glance, January to December heating degree days (base 65°F), contiguous US and statewide (https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/statewide/time-series/7/hdd/12/12/1895-2025/data.json)
- Publisher page: https://invokely.ai/en/publishers/noaa-ncei
- Retrieved: 2026-10-12
- License: Public domain (US government work); NCEI asks users to cite the nClimDiv dataset
- Citation: 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/statewide/time-series/7/hdd/12/12/1895-2025/data.json. Retrieved 2026-10-12.
- Web page: https://invokely.ai/en/heating-degree-days/delaware
- API: https://invokely.ai/api/v1/series?indicator=heating_degree_days_annual&place=us-state-10

| Period | degree days (base 65°F) |
|---|---:|
| 2025 | 4,547 |
| 2024 | 4,037 |
| 2023 | 3,843 |
| 2022 | 4,481 |
| 2021 | 4,164 |
| 2020 | 3,999 |
| 2019 | 4,347 |
| 2018 | 4,472 |
| 2017 | 4,034 |
| 2016 | 4,236 |
| 2015 | 4,480 |
| 2014 | 4,911 |
| 2013 | 4,578 |
| 2012 | 3,850 |
| 2011 | 4,252 |
| 2010 | 4,584 |
| 2009 | 4,608 |
| 2008 | 4,407 |
| 2007 | 4,477 |
| 2006 | 4,006 |
| 2005 | 4,746 |
| 2004 | 4,589 |
| 2003 | 4,940 |
| 2002 | 4,246 |
| 2001 | 4,349 |
| 2000 | 4,735 |
| 1999 | 4,373 |
| 1998 | 3,958 |
| 1997 | 4,708 |
| 1996 | 5,006 |
| 1995 | 4,808 |
| 1994 | 4,801 |
| 1993 | 4,894 |
| 1992 | 4,876 |
| 1991 | 4,227 |
| 1990 | 3,944 |
| 1989 | 5,091 |
| 1988 | 5,171 |
| 1987 | 4,901 |
| 1986 | 4,750 |
| 1985 | 4,559 |
| 1984 | 4,849 |
| 1983 | 4,832 |
| 1982 | 4,918 |
| 1981 | 5,146 |
| 1980 | 5,176 |
| 1979 | 4,990 |
| 1978 | 5,422 |
| 1977 | 4,942 |
| 1976 | 5,077 |
| 1975 | 4,614 |
| 1974 | 4,693 |
| 1973 | 4,575 |
| 1972 | 5,060 |
| 1971 | 4,850 |
| 1970 | 5,149 |
| 1969 | 5,232 |
| 1968 | 5,115 |
| 1967 | 5,349 |
| 1966 | 5,273 |
| 1965 | 5,152 |
| 1964 | 4,916 |
| 1963 | 5,267 |
| 1962 | 5,294 |
| 1961 | 5,170 |
| 1960 | 5,209 |
| 1959 | 4,653 |
| 1958 | 5,510 |
| 1957 | 4,763 |
| 1956 | 4,863 |
| 1955 | 5,001 |
| 1954 | 4,680 |
| 1953 | 4,400 |
| 1952 | 4,802 |
| 1951 | 4,780 |
| 1950 | 4,891 |
| 1949 | 4,350 |
| 1948 | 5,043 |
| 1947 | 5,059 |
| 1946 | 4,389 |
| 1945 | 4,898 |
| 1944 | 5,108 |
| 1943 | 5,169 |
| 1942 | 4,938 |
| 1941 | 4,810 |
| 1940 | 5,710 |
| 1939 | 4,815 |
| 1938 | 4,653 |
| 1937 | 4,990 |
| 1936 | 5,175 |
| 1935 | 5,248 |
| 1934 | 5,384 |
| 1933 | 4,840 |
| 1932 | 4,666 |
| 1931 | 4,552 |
| 1930 | 4,986 |
| 1929 | 4,828 |
| 1928 | 5,136 |
| 1927 | 4,775 |
| 1926 | 5,558 |
| 1925 | 5,050 |
| 1924 | 5,390 |
| 1923 | 4,977 |
| 1922 | 4,904 |
| 1921 | 4,374 |
| 1920 | 5,306 |
| 1919 | 4,803 |
| 1918 | 5,155 |
| 1917 | 5,858 |
| 1916 | 5,287 |
| 1915 | 5,011 |
| 1914 | 5,351 |
| 1913 | 4,362 |
| 1912 | 5,308 |
| 1911 | 4,973 |
| 1910 | 5,165 |
| 1909 | 5,041 |
| 1908 | 4,941 |
| 1907 | 5,550 |
| 1906 | 4,973 |
| 1905 | 5,381 |
| 1904 | 6,030 |
| 1903 | 5,132 |
| 1902 | 5,115 |
| 1901 | 5,585 |
| 1900 | 4,938 |
| 1899 | 5,277 |
| 1898 | 4,924 |
| 1897 | 5,051 |
| 1896 | 5,124 |
| 1895 | 5,517 |