# Heating degree days in Connecticut

Heating degree days in Connecticut was 5,765 degree days (base 65°F) in 2025. Source: NOAA National Centers for Environmental Information.

- Indicator id: `heating_degree_days_annual`
- Place id: `us-state-09`
- 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/6/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/6/hdd/12/12/1895-2025/data.json. Retrieved 2026-10-12.
- Web page: https://invokely.ai/en/heating-degree-days/connecticut
- API: https://invokely.ai/api/v1/series?indicator=heating_degree_days_annual&place=us-state-09

| Period | degree days (base 65°F) |
|---|---:|
| 2025 | 5,765 |
| 2024 | 5,202 |
| 2023 | 5,057 |
| 2022 | 5,627 |
| 2021 | 5,410 |
| 2020 | 5,344 |
| 2019 | 5,937 |
| 2018 | 5,739 |
| 2017 | 5,440 |
| 2016 | 5,364 |
| 2015 | 5,938 |
| 2014 | 6,205 |
| 2013 | 5,930 |
| 2012 | 5,028 |
| 2011 | 5,605 |
| 2010 | 5,524 |
| 2009 | 6,103 |
| 2008 | 5,908 |
| 2007 | 5,945 |
| 2006 | 5,416 |
| 2005 | 6,178 |
| 2004 | 6,148 |
| 2003 | 6,458 |
| 2002 | 5,697 |
| 2001 | 5,672 |
| 2000 | 6,108 |
| 1999 | 5,614 |
| 1998 | 5,236 |
| 1997 | 6,140 |
| 1996 | 6,270 |
| 1995 | 6,145 |
| 1994 | 6,241 |
| 1993 | 6,270 |
| 1992 | 6,378 |
| 1991 | 5,477 |
| 1990 | 5,370 |
| 1989 | 6,445 |
| 1988 | 6,429 |
| 1987 | 6,119 |
| 1986 | 6,124 |
| 1985 | 6,115 |
| 1984 | 6,118 |
| 1983 | 6,026 |
| 1982 | 6,332 |
| 1981 | 6,334 |
| 1980 | 6,496 |
| 1979 | 6,091 |
| 1978 | 6,790 |
| 1977 | 6,327 |
| 1976 | 6,548 |
| 1975 | 6,029 |
| 1974 | 6,276 |
| 1973 | 5,803 |
| 1972 | 6,608 |
| 1971 | 6,346 |
| 1970 | 6,558 |
| 1969 | 6,432 |
| 1968 | 6,499 |
| 1967 | 6,709 |
| 1966 | 6,460 |
| 1965 | 6,505 |
| 1964 | 6,302 |
| 1963 | 6,592 |
| 1962 | 6,718 |
| 1961 | 6,398 |
| 1960 | 6,374 |
| 1959 | 6,088 |
| 1958 | 6,808 |
| 1957 | 5,984 |
| 1956 | 6,458 |
| 1955 | 6,362 |
| 1954 | 6,075 |
| 1953 | 5,526 |
| 1952 | 6,045 |
| 1951 | 6,006 |
| 1950 | 6,361 |
| 1949 | 5,717 |
| 1948 | 6,518 |
| 1947 | 6,467 |
| 1946 | 5,966 |
| 1945 | 6,315 |
| 1944 | 6,488 |
| 1943 | 6,758 |
| 1942 | 6,297 |
| 1941 | 6,202 |
| 1940 | 7,096 |
| 1939 | 6,561 |
| 1938 | 6,130 |
| 1937 | 6,244 |
| 1936 | 6,492 |
| 1935 | 6,661 |
| 1934 | 6,718 |
| 1933 | 6,303 |
| 1932 | 6,053 |
| 1931 | 5,906 |
| 1930 | 6,253 |
| 1929 | 6,440 |
| 1928 | 6,477 |
| 1927 | 6,255 |
| 1926 | 7,147 |
| 1925 | 6,453 |
| 1924 | 6,891 |
| 1923 | 6,743 |
| 1922 | 6,423 |
| 1921 | 5,982 |
| 1920 | 6,873 |
| 1919 | 6,361 |
| 1918 | 6,746 |
| 1917 | 7,593 |
| 1916 | 6,922 |
| 1915 | 6,352 |
| 1914 | 6,854 |
| 1913 | 5,909 |
| 1912 | 6,815 |
| 1911 | 6,549 |
| 1910 | 6,506 |
| 1909 | 6,543 |
| 1908 | 6,376 |
| 1907 | 7,139 |
| 1906 | 6,566 |
| 1905 | 6,932 |
| 1904 | 7,605 |
| 1903 | 6,609 |
| 1902 | 6,513 |
| 1901 | 6,994 |
| 1900 | 6,366 |
| 1899 | 6,683 |
| 1898 | 6,396 |
| 1897 | 6,552 |
| 1896 | 6,803 |
| 1895 | 6,840 |