Annual number of nights of thermal discomfort

Figure Created 21 Jun 2016 Published 30 Jan 2017 Last modified 09 Feb 2017
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The map shows that southern cities can experience daytime conditions that represent slight to moderate heat stress at the very least. Many southern cities have also a high share of elderly people. The map does not yet show future projections of thermal discomfort in cities, although it is expected that discomfort in more northern cities will increase.

European data


Additional information

The mean number of hot days combined with tropical nights increases southward. In the future, it is expected that the number of such days will grow across Europe. In cities, this effect is intensified further due to the urban heat island effect.

Whether citizens feel comfortable or not depends not only on the actual air temperature, but also on the complex interaction of several physical, physiological, behavioural, and psychological factors. The Thermal Comfort Index attempts to capture these relations and the comfort/discomfort levels they generate. From a health perspective, thermal comfort at night is crucial, as the human body needs to maintain reasonable levels for sleep and rest. The mortality risk, particularly among elderly, young and sick people increases with thermal discomfort.


Geographic coverage

Temporal coverage


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