A severe heatwave tightened its grip on western Europe on Thursday, toppling June temperature records in multiple countries and prompting France to place three-quarters of the nation under its highest-level red alert. Switzerland recorded its hottest-ever June temperature as Basel reached 38C (100.4F), breaking a record set eight decades earlier, while in Britain the southwestern county of Somerset hit 36.4C, surpassing the previous day's national June high.
The scale of the heat is continental. Forecasters estimated that some 380 million people across Europe were experiencing temperatures above 30C, with about 101 million enduring conditions hotter than 35C. In France alone, roughly 50 million people faced temperatures above 35C; in Germany, about 70 million were exposed to heat over 30C. Spain logged its highest June daily-average temperatures since records began in 1950.
The human cost is mounting. Spanish authorities have linked approximately 212 deaths to the heat between Sunday and Wednesday, and in France the toll has been driven in part by a grim secondary hazard: dozens of people have drowned since June 18 while swimming in unsupervised rivers, lakes and quarries to escape the heat, many of them young, according to French officials. A three-year-old was found dead in a parked car in Saint-Gratien, the third child heat death in France this week.
This is the second and more intense heatwave to strike Europe since mid-June, part of a summer that has repeatedly pushed the mercury into dangerous territory. Red and amber heat warnings have been issued across France, Spain, Germany, Switzerland, Italy, the United Kingdom and beyond, with authorities urging people to stay indoors during peak afternoon hours, check on vulnerable neighbors and avoid unsupervised swimming.
Infrastructure has begun to strain. Heat-related equipment failures knocked out power to tens of thousands of households in France's Brittany region, and transport operators across the continent have warned of speed restrictions and delays as rails and roads bake. Extreme heat reduces the efficiency of power generation even as it sends demand for cooling soaring, a combination that stresses electricity grids precisely when they are needed most.
Scientists have repeatedly linked the rising frequency, intensity and duration of European heatwaves to human-caused climate change, which has made the continent the fastest-warming on Earth. Events that were once rare are now arriving earlier in the season and lasting longer, giving bodies, buildings and power systems less time to recover between extremes.
The immediate forecast offered little relief, with the most intense heat expected to persist through Friday across much of France and central Europe before a gradual cooling. Health agencies cautioned that the danger does not end when temperatures peak: heat stress accumulates over consecutive days and nights that stay warm, and the full mortality toll of a heatwave typically becomes clear only weeks later, once excess-death figures are tallied.