When the temperature rises in Paris, the heat often feels much more intense than elsewhere. This sensation is not just a feeling—it is a well-documented phenomenon known as the urban heat island effect. And according to several recent scientific studies, the French capital ranks among the European cities most exposed to its effects.
A study published in *The Lancet Planetary Health* analyzed more than 800 European cities to assess their vulnerability to extreme heat. Paris emerged as one of the cities where the health consequences of heat waves are most concerning.
One of the worst European cities for enduring a heat wave
The problem isn’t just the temperatures recorded by weather stations. Much of the difficulty lies in the way the city was built. Concrete, asphalt, mineral-based facades, and dark roofs absorb heat throughout the day before gradually releasing it at night. As a result, while neighboring rural areas begin to cool down after sunset, certain Parisian neighborhoods continue to retain significant heat for several hours.
During the 2003 heat wave, temperature differences of several degrees were observed between the heart of Paris and the region’s large forested areas. In some heavily built-up areas, temperatures can even remain high throughout the night, preventing residents from recovering properly.
Urban density further exacerbates the phenomenon. Closely spaced buildings sometimes form veritable heat traps where air circulates with difficulty. Narrow streets, large housing complexes, and certain business districts with a high proportion of hard surfaces limit the natural dissipation of hot air.
Conversely, elements capable of lowering temperatures remain relatively scarce across the city. Yet water, natural soils, and especially trees playan essential role. Thanks to the shade they provide and through evapotranspiration, green spaces can significantly reduce the perceived temperature.
This, in fact, explains the sometimes dramatic differences observed between certain neighborhoods. Areas near large parks, wooded areas, or tree-lined residential neighborhoods are often much more pleasant during heat waves than the densely populated neighborhoods of northeastern Paris or certain highly urbanized areas of the inner suburbs.
In light of this, local governments are ramping up greening projects. Urban forests, tree plantings, schoolyards transformed into cool oases, and the removal of impervious surfaces are now among the main strategies being considered to help the capital adapt to climate change.
For while Paris remains one of Europe’s most attractive cities, its urban design was conceived at a time when heat waves were much rarer. With global warming, the issue is no longer simply about making the city more pleasant; it is now about making it more livable during the summers to come.
