The need for air conditioning is increasing in the EU

Recent Eurostat figures show an increase in the number of cooling degree days in the EU-27 Member States. This indicates an increase in the need for air conditioning over the last decades.

Heating degree days (HDD) and Cooling degree days (CDD) are weather-based technical indexes designed to describe the energy requirements of buildings in terms of heating (HDD) or cooling (CDD). Both variables are derived from measurements of outside air temperature. [1] 


Simply put, HDDs are a measure of the amount (in degrees) and duration (in days) of outdoor air temperature below a specific base temperature (or "balance point"). CDDs are a measure of the amount (in degrees) and duration (in days) of outdoor air temperature below a specific base temperature. [2] For the calculation of CDD, the base temperature is defined as the highest daily average air temperature which does not require indoor cooling. Its value depends on several factors associated with the building and its surrounding environment. [1] 


According to figures published by Eurostat, CDD values in the EU-27 (excluding the United Kingdom) were more than twice as high in 2020 as in 1979, rising from a value of 37 in 1979 to 99 in 2020. This suggests an increase in cooling requirements (air conditioning) over the last decades. The average CDD value for the EU-27 is 72. After 2001, only a few years (2002, 2004, 2005 and 2014) were below the average. [1]


Conversely, the heating degree days value decreased by 21% between 1979 (3 510 days) and 2020 (2 759 days) in the EU-27, suggesting that the need to heat buildings has decreased over time. 


Cooling degree days vary across the EU. In 2020, the countries with the highest values were Cyprus (803), Malta (672) and Greece (345). This means that in 2020, a building in Cyprus, Malta and Greece would have greater needs for air conditioning than the rest of the EU, because higher temperatures (over 24°C) were more frequent. The lowest CDD index calculated were observed in Ireland (0.00), Sweden (0.08) and Finland (0.42). [1]  




[1] Eurostats. Heating and cooling degree days. 

[2] So what are degree days? 

[3] European Environment Agency (EEA). Heating and cooling degree days.