“What the July heat wave had was this kind of southern spike toward record-breaking temperatures, really with days of really extreme heat temperatures, where this week is more of a prolonged spell of temperatures, but not quite as hot,” Stephen Dixon, a spokesman for the Met Office, said on Tuesday by phone.
“There are potential impacts from prolonged heat of this nature,” he said. “I think it’s important to note that nighttime temperatures for some areas in the south won’t drop below” 20 degrees Celsius (68 Fahrenheit).
Scattered thunderstorms could bring a bit of rain across the southwest and into some central areas on Sunday, Mr. Dixon said, adding that there was a chance for more rain next week.
There were also concerns that the hot weather could affect transportation, with at least one official from Britain’s National Highways advising motorists to thoroughly check their vehicles before setting out.