Europe's heatwave looks set to peak on Tuesday, but temperatures may remain above normal into the middle of next week, the World Meteorological Organization said, warning that such events could occur with greater frequency in the future.
"The question that everybody is asking looking ahead is - when is this going to end?," said Robert Stefanski, chief of Applied Climate Services at the WMO. "Unfortunately, looking at all the models from all our partners at a national and regional level, possibly not until middle of next week."
Britain recorded its highest-ever temperature of 40 degrees Celsius, while firefighters in southwestern France battled to contain huge forest wildfires as a heatwave rising from the south settled over western Europe.
Stefanski said he expected temperatures to peak on Tuesday but to stay above average.
At the same briefing, WMO secretary-general Petteri Taalas warned that he expected to see a "much higher" number of heat waves in future due to climate change.
"The direction is clear and in the future these kind of heat waves are going to be normal and we will see even stronger extremes," said Taalas, wearing short sleeves and a red and blue tie which he said he chose to illustrate the warming trend.
Officials at the same press briefing said they expected more deaths among the elderly and those with pre-existing health conditions due to the ongoing heat wave as well as challenges for health systems due to increased demand.