Cooling and heating degree days - Cities and FUAs by country
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...
What the numbers show
Cooling and heating degree days - Cities and FUAs is currently reported for 2 countries. The highest value is 1,998 Degree days in Luxembourg; the lowest is 162.92 Degree days in Armenia.
The median across all reporting countries is 1,081 Degree days, and the mean is 1,081 Degree days.
The gap between the highest and lowest reporting country is a factor of about 12.
Cooling and heating degree days - Cities and FUAs: full country ranking
| # | Country | Latest | Year | 10-year change | Trend |
|---|---|---|---|---|---|
| 1 | Luxembourg | 1,998 Degree days | 2025 | down 10.9% | falling |
| 2 | Armenia | 162.92 Degree days | 2025 | down 1.1% | falling |
Regions and income groups
Aggregates are excluded from the country ranking above so that a region can never outrank a country.
- Innsbruck 4,806 Degree days
- Santiago 1,815 Degree days
- Saskatoon 4,661 Degree days
- Nantes 1,385 Degree days
- Regina 4,431 Degree days
- Treviso 1,336 Degree days
- Edmonton 4,365 Degree days
- Sacramento 1,152 Degree days
- Erzurum 4,223 Degree days
- Toledo 1,060 Degree days
- Calgary 4,146 Degree days
- Braga 885.34 Degree days
- Oulu/Uleåborg 4,133 Degree days
- Porto 747.72 Degree days
- Asahikawa 4,115 Degree days
- Coimbra 654.05 Degree days
- Red Deer 4,103 Degree days
- Valparaíso 643.62 Degree days
- Oslo 4,051 Degree days
- Verviers 4,050 Degree days
- Reykjavík 3,918 Degree days
- Jyväskylä 3,855 Degree days
- Punta Arenas 3,772 Degree days
- Winnipeg 3,771 Degree days
- Boulder 3,762 Degree days
- Larimer 3,750 Degree days
- Stavanger 3,742 Degree days
- Kuopio 3,727 Degree days
- Sherbrooke 3,725 Degree days
- Cass 3,719 Degree days
- Sapporo 3,679 Degree days
- Obihiro 3,678 Degree days
- Bamberg 3,622 Degree days
- Ottawa 3,599 Degree days
- Montreal 3,597 Degree days
- Trenčín 3,595 Degree days
- Umeå 3,595 Degree days
- Turku/Åbo 3,584 Degree days
- Benton (MN) 3,569 Degree days
- Trondheim 3,462 Degree days
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