France, Britain, and Spain endure a record-breaking early summer heat wave, with 40 drowning deaths in France and widespread disruptions as millions of people lack air conditioning.

What happened

A severe heat wave swept across Europe on Tuesday, placing 54 French departments—roughly half the country—under red heat wave alert. Temperatures are expected to remain above 40 degrees Celsius (104 degrees Fahrenheit) in many towns at least until the end of the week. Britain's Met Office issued a red extreme heat warning for Wednesday and Thursday, with forecasts of at least 39 degrees Celsius (102.2 degrees Fahrenheit) in southern regions. Spain's weather service issued red alerts for temperatures of 44 degrees Celsius (111 degrees Fahrenheit) in southern Andalusia. Forty people have died by drowning in France since last Thursday, mainly young people, as residents seek relief from the searing heat.

What to watch

Meteo France said that further record-breaking temperatures are expected, including some that could surpass all previous records. Spain's Aemet meteorologist noted that of the dozen heat waves recorded in June since 1975, half have occurred since 2015, indicating that heat waves are becoming more frequent and appearing outside the traditional July and August window. Conditions are expected to ease in Britain by Friday, but the intensity and duration of the broader European heat wave remain uncertain.