A third extreme heatwave of the summer is affecting much of western and southern Europe, with local temperature records broken in Spain, France, and Italy. In Barcelona, the Fabra observatory recorded 40.7°C on Wednesday, the highest in 112 years of data, according to the Catalan meteorological agency Meteocat. Marseille-Marignane station in southern France reached 40.5°C, a first since records began in 1921, while several Italian cities, including Milan and Turin, saw temperatures near 39°C, with the Piedmont region describing the day as ‘historic’. The UK Health Security Agency issued an amber heat health alert for much of England, warning of significant impacts on health services and a likely rise in deaths among older and vulnerable people.

Health authorities across the continent report that the current wave follows a June heatwave that caused excess mortality. In France, more than 1,000 additional deaths were recorded between 24 June and early July, according to the national public health agency. Spanish officials reported at least 1,028 heat-related deaths during the same period. The World Health Organization’s regional director for Europe, Hans Kluge, warned that ‘further lethal weeks could await the European region’ and noted that fewer than half of member states have national heat-health action plans. In Milan, the city council issued an ordinance requiring delivery platforms to reduce or suspend assignments during the hottest afternoon hours to protect riders. Tourists in Barcelona described sleeping without air conditioning as ‘impossible’ and reported heat warnings broadcast on public beaches.

Environmental strain is mounting. Nearly 20,000 hectares of forest have burned in Portugal, Spain, France, and Greece this summer, with thousands evacuated from suburbs of Thessaloniki and southern French towns. In Italy, high water temperatures—reaching 32°C in the Adriatic lagoons—have caused sudden die-offs of mussels and clams, with losses estimated at 1,000 quintals of mussels and up to 90% of clams in some areas, according to fishing cooperatives. Lakes across Italy are also under pressure: the Maggiore, Como, and Iseo lakes have seen water levels drop sharply, while the Trasimeno lake in central Italy has lost 169 centimetres relative to its hydrometric zero, restricting boat navigation. Urban heat island data from the Mirificus project show surface temperatures in Italian cities regularly exceeding 40°C, with Florence reaching 44°C and Rome 43.7°C.

Scientists from the World Weather Attribution network have concluded that the heatwave would not have been possible without human-caused climate change, ruling out natural weather phenomena as the primary driver. The current heat dome, an anticyclone trapping hot air, is expected to persist for several more days, though forecasters in the UK and France note that temperatures may not surpass the all-time highs of June. Authorities continue to monitor the situation, with heat warnings in effect across Andorra, France, Portugal, Spain, Switzerland, and the United Kingdom.