French public health authorities have recorded 5,764 more deaths than expected during the heatwave that struck the country between 17 June and 2 July, the highest excess mortality linked to extreme heat since the devastating 2003 episode. The toll, published by Santé publique France on Wednesday, compares 21,674 deaths from all causes in affected regions against a statistically modelled baseline of 15,910, yielding a 36 per cent increase. The agency described the event as “unprecedented” for its early onset, intensity and duration, noting that 98.5 per cent of the metropolitan population was exposed while schools and workplaces remained open.

More than half of the excess deaths occurred in a three-day window from 25 to 27 June, coinciding with the hottest days ever recorded nationwide—average temperatures reached 30°C, with peaks above 40°C in many areas. The Île-de-France region around Paris was hardest hit, registering 1,999 unexpected deaths, roughly 80 per cent above normal. People aged 75 and older accounted for about two-thirds of the provisional total, though the agency observed a marked rise in mortality from age 45 onward, a pattern it called “unprecedented” for a heatwave.

Nearly half of those who died passed away in hospitals, which faced surges of patients with heat-related illnesses; about a third died at home, and the remainder in care homes for the elderly. The figures remain provisional and are based on all-cause mortality, meaning a direct causal link to heat has not been established for each death. Final data, expected in the autumn, will allow a more precise attribution. The initial estimate by the health minister in late June had put excess deaths at around 2,025, a figure now sharply revised upward.

The 2003 heatwave, which caused an estimated 15,000 deaths in France, remains the country’s deadliest. The current toll, while lower, is the highest recorded since then and comes as much of southern Europe contends with extreme temperatures and wildfires. French authorities stress that the count will be refined as more complete mortality data become available, and that many heat-related deaths are never formally classified as such because underlying conditions are often listed as the immediate cause.