The Mediterranean Sea was up to 6 degrees Celsius warmer than usual for the time of year, hitting a record of as much as 30 C (86 F) in Spain's Balearic Sea as a heat dome trapped hot air above Europe, the country's Aemet weather forecaster said.

The heat was so expansive that mountaintops, including the French Alps, that are usually frozen from snowpack saw record temperatures. Heat records were set for June in Spain and Portugal.

Europe is sweltering under an intense heatwave, as temperatures soar across Spain, Portugal, France and Italy for one of the hottest summer starts ever recorded.