Western Europe endured its hottest June on record as a marine heatwave in the Mediterranean amplified two successive land heatwaves, according to new data from the European Union’s Copernicus Climate Change Service. The region’s average temperature reached 20.49 °C, surpassing the previous June record set in 2003, while the global mean of 16.46 °C made the month the third-warmest June worldwide. Copernicus said high-pressure ‘heat-domes’ kept daytime air temperatures above 40 °C across Spain, Portugal, France, Italy and Germany between 17-22 June and again from 30 June to 2 July. Thermometers climbed to 46 °C in parts of Spain and Portugal, Barcelona logged its hottest June in more than a century, and France placed several departments on red alert, closing more than 1,300 schools. Portuguese health authorities linked the late-June episode to 69 excess deaths, mostly among the elderly. At sea, almost the entire western Mediterranean experienced water temperatures more than 5 °C above normal. The French meteorological service measured 26.04 °C along the country’s Mediterranean coastline on 30 June—the highest June reading on record—while Copernicus reported a basin-wide daily record of 27 °C and spot anomalies of +6.4 °C near Ibiza, where waters reached 31 °C. Researchers call the event one of the most severe marine heatwaves ever observed in the basin. Scientists warn that the Mediterranean is warming roughly 20 % faster than the global average, creating a feedback loop that elevates humidity, prolongs tropical nights and intensifies heat stress on land. Copernicus said the combination of record sea-surface temperatures and persistent atmospheric highs demonstrates how climate change is making European heatwaves more frequent, longer and more dangerous.