The UK provisionally recorded its highest-ever temperature on 19 July, with a reading of more than 40 degrees Celsius — 104 degrees Fahrenheit at Heathrow.

“I suspect this record is going to be broken several times over the course of the day,” said Bob Ward, the communications director of the Grantham Research Institute on Climate Change and the Environment. “Peak temperatures are around 3 or 4 in the afternoon. The record will undoubtedly be smashed.”