Cooling and heating degree days - Cities and FUAs (heating Cities) in Reykjavik
Reykjavik: Cooling and heating degree days - Cities and FUAs (heating Cities) was 3,918 Degree days in 2025. ▼ Falling
Cooling and heating degree days - Cities and FUAs in Reykjavik, 1950–2025
Source: Organisation for Economic Co-operation and Development. Measured in Degree days.
Analysis
Reykjavik recorded 3,918 Degree days for cooling and heating degree days - cities and fuas in 2025. That is the lowest value across all 76 years on record.
Compared with earlier readings it is down 18.7% on the previous year and down 13.7% over ten years.
Over the whole period, cooling and heating degree days - cities and fuas in Reykjavik peaked at 5,318 Degree days in 1979 and was at its lowest, 3,918 Degree days, in 2025.
Reykjavik ranks 12th of 1314 regions on this measure, in the top 10%.
The long-run direction has been consistently falling across the 76 years of available data.
Cooling and heating degree days - Cities and FUAs (heating Cities) in Reykjavik, year by year
| Year | Degree days | Change |
|---|---|---|
| 1950 | 4,612 Degree days | — |
| 1951 | 4,818 Degree days | +4.5% |
| 1952 | 4,584 Degree days | -4.9% |
| 1953 | 4,341 Degree days | -5.3% |
| 1954 | 4,474 Degree days | +3.1% |
| 1955 | 4,735 Degree days | +5.8% |
| 1956 | 4,347 Degree days | -8.2% |
| 1957 | 4,614 Degree days | +6.2% |
| 1958 | 4,671 Degree days | +1.2% |
| 1959 | 4,666 Degree days | -0.1% |
| 1960 | 4,338 Degree days | -7.0% |
| 1961 | 4,730 Degree days | +9.1% |
| 1962 | 4,828 Degree days | +2.1% |
| 1963 | 4,716 Degree days | -2.3% |
| 1964 | 4,317 Degree days | -8.5% |
| 1965 | 4,586 Degree days | +6.2% |
| 1966 | 5,013 Degree days | +9.3% |
| 1967 | 4,866 Degree days | -2.9% |
| 1968 | 4,789 Degree days | -1.6% |
| 1969 | 5,203 Degree days | +8.7% |
| 1970 | 4,961 Degree days | -4.7% |
| 1971 | 4,736 Degree days | -4.5% |
| 1972 | 4,454 Degree days | -6.0% |
| 1973 | 4,868 Degree days | +9.3% |
| 1974 | 4,428 Degree days | -9.0% |
| 1975 | 4,732 Degree days | +6.9% |
| 1976 | 4,624 Degree days | -2.3% |
| 1977 | 4,775 Degree days | +3.3% |
| 1978 | 4,908 Degree days | +2.8% |
| 1979 | 5,318 Degree days | +8.4% |
| 1980 | 4,631 Degree days | -12.9% |
| 1981 | 5,032 Degree days | +8.7% |
| 1982 | 4,856 Degree days | -3.5% |
| 1983 | 5,032 Degree days | +3.6% |
| 1984 | 4,826 Degree days | -4.1% |
| 1985 | 4,666 Degree days | -3.3% |
| 1986 | 4,764 Degree days | +2.1% |
| 1987 | 4,167 Degree days | -12.5% |
| 1988 | 4,796 Degree days | +15.1% |
| 1989 | 4,781 Degree days | -0.3% |
| 1990 | 4,492 Degree days | -6.0% |
| 1991 | 4,266 Degree days | -5.0% |
| 1992 | 4,680 Degree days | +9.7% |
| 1993 | 4,593 Degree days | -1.9% |
| 1994 | 4,832 Degree days | +5.2% |
| 1995 | 4,898 Degree days | +1.4% |
| 1996 | 4,509 Degree days | -7.9% |
| 1997 | 4,371 Degree days | -3.0% |
| 1998 | 4,586 Degree days | +4.9% |
| 1999 | 4,713 Degree days | +2.8% |
| 2000 | 4,666 Degree days | -1.0% |
| 2001 | 4,340 Degree days | -7.0% |
| 2002 | 4,277 Degree days | -1.5% |
| 2003 | 4,030 Degree days | -5.8% |
| 2004 | 4,132 Degree days | +2.5% |
| 2005 | 4,267 Degree days | +3.3% |
| 2006 | 4,184 Degree days | -1.9% |
| 2007 | 4,208 Degree days | +0.6% |
| 2008 | 4,408 Degree days | +4.7% |
| 2009 | 4,271 Degree days | -3.1% |
| 2010 | 4,037 Degree days | -5.5% |
| 2011 | 4,340 Degree days | +7.5% |
| 2012 | 4,187 Degree days | -3.5% |
| 2013 | 4,388 Degree days | +4.8% |
| 2014 | 4,154 Degree days | -5.3% |
| 2015 | 4,540 Degree days | +9.3% |
| 2016 | 4,032 Degree days | -11.2% |
| 2017 | 4,196 Degree days | +4.1% |
| 2018 | 4,327 Degree days | +3.1% |
| 2019 | 4,120 Degree days | -4.8% |
| 2020 | 4,364 Degree days | +5.9% |
| 2021 | 4,182 Degree days | -4.2% |
| 2022 | 4,307 Degree days | +3.0% |
| 2023 | 4,573 Degree days | +6.2% |
| 2024 | 4,821 Degree days | +5.4% |
| 2025 | 3,918 Degree days | -18.7% |
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1950s | 4,586 Degree days | 4,341 Degree days | 4,818 Degree days | 10 |
| 1960s | 4,739 Degree days | 4,317 Degree days | 5,203 Degree days | 10 |
| 1970s | 4,780 Degree days | 4,428 Degree days | 5,318 Degree days | 10 |
| 1980s | 4,755 Degree days | 4,167 Degree days | 5,032 Degree days | 10 |
| 1990s | 4,594 Degree days | 4,266 Degree days | 4,898 Degree days | 10 |
| 2000s | 4,278 Degree days | 4,030 Degree days | 4,666 Degree days | 10 |
| 2010s | 4,232 Degree days | 4,032 Degree days | 4,540 Degree days | 10 |
| 2020s | 4,361 Degree days | 3,918 Degree days | 4,821 Degree days | 6 |
More reference data data for Reykjavik
- Cooling and heating degree days - Cities and FUAs — Cooling degree -100 % change on previous year (2021)
- Cooling and heating degree days - Cities and FUAs — Change in cooling 0 % change on previous year (2025)
- Cooling and heating degree days - Cities and FUAs, annual growth rate -18.73 % change on previous year (2025)
- Cooling and heating degree days - Cities and FUAs — Change in heating -302.25 % change on previous year (2025)
- Cooling and heating degree days - Cities and FUAs — Change in heating -604.17 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs — Change in cooling -0.0689 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs — Cooling degree 0 Degree days (2025)
- Precipitation - Cities and FUAs — Extreme precipitation days 5 Days per year (2024)
- Precipitation - Cities and FUAs — Change in extreme precipitation -3.48 Days per year (2024)
- Dependency ratio - Cities and FUAs 23 Percentage of population aged 15-64 years (2025)
Frequently asked questions
- What is cooling and heating degree days - cities and fuas in Reykjavik?
- Cooling and heating degree days - cities and fuas in Reykjavik was 3,918 Degree days in 2025, according to Organisation for Economic Co-operation and Development.
- What is the highest cooling and heating degree days - cities and fuas recorded in Reykjavik?
- The highest recorded value was 5,318 Degree days in 1979.
- What is the lowest cooling and heating degree days - cities and fuas recorded in Reykjavik?
- The lowest recorded value was 3,918 Degree days in 2025.
- How does Reykjavik rank for cooling and heating degree days - cities and fuas?
- Reykjavik ranks 12th out of 1314 regions with data for 2025.
- Is cooling and heating degree days - cities and fuas rising or falling in Reykjavik?
- Over the last ten years it is down 13.7%. The long-run trend across the full record is falling.
- Where does this Reykjavik data come from?
- The figures come from Organisation for Economic Co-operation and Development, published as part of Cooling and heating degree days - Cities and FUAs. Statizoid updates them automatically from the source API.
Download this data
CSV · JSON — 76 observations, free to reuse under OECD Terms and Conditions (attribution required).
About this data
This dataset provides indicators of Cooling and Heating Degree Days (CDDs and HDDs) for FUAs and cities. CDDs and HDDs are measurements used to estimate energy usage based on outdoor temperature. CDD measures the demand for cooling, while HDD measures the demand for heating, both calculated relative to a baseline temperature. Data sources and methodology The indicators use 0.1-degree resolution grids from the ERA5-Land dataset. ERA5-Land is used as it provides harmonised, globally consistent coverage at fine spatial resolution (0.1 degree), enabling the production of comparable subnational indicators also where national meteorological data are not available at the required scale. Annual CDDs are the sum over a year of the differences between the daily mean outdoor air temperature and the threshold temperature when the outdoor temperature is above the threshold temperature. HDDs are the sum over a year of the differences between the threshold temperature and the daily mean outdoor air temperature when the outdoor temperature is below the threshold temperature. Threshold temperatures are set to 22°C for CDDs and 15°C for HDDs. These estimates may differ from official subnational climate statistics due to differences in methodological approaches, such as the use of reanalysis based top down modelling versus in situ observations, along with variations in input data sources, spatial resolution, and the models and algorithms used to generate temperature estimates. Defining FUAs and cities The OECD, in cooperation with the EU, has developed a harmonised definition of functional urban areas (FUAs) to capture the economic and functional reach of cities based on daily commuting patterns (OECD, 2012). FUAs consist of: A city – defined by urban centres in the degree of urbanisation, adapted to the closest local administrative units to define a city. A commuting zone – including all local areas where at least 15% of employed residents work in the city. The delineation process includes: Assigning municipalities surrounded by a single FUA to that FUA. Excluding non-contiguous municipalities. The correspondence table between SAUs and FUAs/cities is available in parquet and csv format. The definition identifies 1 272 FUAs and 1 269 cities in all OECD member countries except Costa Rica and three accession countries. Cite this dataset OECD Regions, cities and local areas database (Cooling and heating degree days - Cities and FUAs), http://oe.cd/geostats Further information OECD Local Data Portal OECD Regions and Cities at a Glance For questions and/or comments, please email CitiesStat@oecd.org