At least 280 excess deaths during the August heatwave, according to Public Health France

At least 280 more deaths than normal, an excess of around 5%, were recorded in France during the heatwave from August 8 to 19, the second of the summer of 2025, the French public health agency announced on Thursday. "This excess mortality is only observed in people aged 75 and over.", specifies the health agency, recalling that it is still too early to establish a direct cause and effect relationship between these deaths and the high temperatures.

Risk of dehydration, worsening of cardiovascular problems, etc.

France, like other European countries, was hit by this heatwave in August, the second of the summer after an initial heatwave in late June and early July. Globally, August was the third hottest month ever recorded. The figures released Thursday by Public Health France provide an initial idea of the mortality rate linked to this heatwave, which affected just under half of France, while the negative effects of extreme heat are well documented: risk of dehydration, worsening of cardiovascular problems, etc.

However, this excess mortality may be linked to other causes, such as the one previously announced for the June-July heatwave: Public Health France estimated it at around 480 excess deaths. These calculations are based on all-cause mortality data from civil registry offices and transmitted by INSEE, compared to an expected death figure based on the previous six years, excluding extreme events.

New Aquitaine and Provence-Alpes-Côte d'Azur particularly affected

But, already, these first data "underline the importance of implementing preventive measures to reduce the impact of heat, during heat waves, but also throughout the summer", warns Public Health France, as heat waves tend to increase against a backdrop of global warming. In detail, the excess mortality observed during the August heatwave particularly affected Nouvelle-Aquitaine and Provence-Alpes-Côte d'Azur. They recorded “each at least 90 excess deaths – +7.9% and +7.7% respectively”, according to the health agency. Public Health France plans to provide a precise assessment of mortality directly attributable to heat later this fall, not only during heatwaves but also throughout the rest of the summer.