Cooling and heating degree days - Regions

This dataset provides indicators on Cooling and Heating Degree Days, in large (TL2) and small (TL3) regions.

Data definition and source

• Cooling Degree Days (CDD) quantify how hot a given period was, indicating the energy demand for cooling buildings. CDD is calculated as the sum of the differences between the daily mean temperature and a reference temperature of 22°C, for all days when the mean temperature exceeds 22°C.


• Heating Degree Days (HDD) quantify how cold a given period was, reflecting the energy demand for heating buildings. HDD is calculated as the sum of the differences between a reference temperature of 15°C and the daily mean temperature, for all days when the mean temperature falls below 15°C.

Definition of regions

Regions are subnational units below national boundaries. OECD countries have two regional levels: large regions (territorial level 2 or TL2) and small regions (territorial level 3 or TL3). For more information, see the OECD Territorial grid (pdf) and the OECD Territorial Correspondence Table (xlsx). 

Cite this dataset

OECD Regions, Cities and Local Areas database http://oe.cd/geostats.

Further information

• OECD Local Data Portal 


• OECD Regions and Cities at a Glance

For questions and/or comments, please email [email protected].