A new heatwave is sweeping across southern Europe, with temperatures forecast to reach 43°C in parts of Portugal and southern Spain, according to national meteorological agencies. The World Health Organization’s European office has warned that the coming days could be “the deadliest weeks” of the summer, as emergency services battle dozens of wildfires that have already forced thousands of residents and tourists to flee their homes.

Portuguese civil protection authorities reported that the country’s largest active fire, in the central Dão region, had consumed more than 13,000 hectares of forest and farmland before being brought under control, though crews remain on high alert for flare-ups. Across the border, Spain’s state meteorological agency issued a red alert for extreme heat in Aragon, Catalonia and Valencia, while firefighters struggled to contain multiple blazes. In Catalonia, a fire in La Bisbal d’Empordà destroyed at least 11 homes and forced the confinement of some 40,000 people, according to regional emergency services. Further south, a wildfire in Grazalema, Cádiz province, prompted the evacuation of more than 100 people. French authorities said a fire in the Pyrenees had burned over 5,000 hectares and led to the evacuation of 10,000 residents, with the Tour de France rerouted for safety. Greece, Croatia and Albania also reported wildfires, with one reaching the outskirts of Thessaloniki and destroying two industrial buildings.

The human toll is still being tallied. The WHO said that France, the Netherlands and Belgium recorded 3,700 excess deaths during the June heatwave, a figure it described as preliminary. Hans Kluge, WHO regional director for Europe, noted that fewer than half of the organisation’s European member states have heat-health action plans in place, leaving vulnerable populations—including nursing home residents and the homeless—inconsistently protected. In the United Kingdom, where a third heatwave of the year is pushing temperatures towards 35°C, the UK Health Security Agency issued amber heat health alerts for the Midlands and southern England. Train operators cancelled services and urged passengers to travel only if essential, citing the risk of buckled rails and sagging overhead wires. A survey commissioned by Greenpeace found that 65 per cent of Britons struggled to sleep during June’s record heat, and 22 per cent threw away food that spoiled.

Climate researchers in France and the United Kingdom attributed the intensity of the June heatwave to a “heat dome” supercharged by human-driven climate change. A rapid attribution study by the ClimaMeter consortium found that such weather patterns are now up to 2.5°C hotter than they were three decades ago, and are becoming more persistent. The same analysis estimated that 327 million people and $15.6 trillion in economic activity were exposed to heat conditions intensified by climate change during that week. As the new heatwave builds, Portuguese authorities have requested precautionary support from Morocco, Spain and the European Union, and the European Commission has dispatched firefighting teams and aircraft from Italy and Spain. Firefighting operations continue across the Mediterranean basin, with provisional damage assessments and investigations into the causes of several blazes still under way.