An amber alert, indicating a “likely” risk of death for vulnerable groups and a greater chance of water-related incidents, was issued for the West Midlands, East Midlands, East of England, South East and South West at 9am on July 8, and will remain in effect until 9pm on July 12.
A yellow alert, indicating the “possibility” of significant impact, was issued during the same timeframe for Yorkshire and the Humber, North West England and North East England.
It comes after the UK officially entered its third heatwave in as many months, with temperatures expected to climb as high as 35C in some areas later this week, according to the Met Office.
Parts of southern England could see highs of 32C on Tuesday, rising to 33C on Wednesday and 34C on Thursday, with the highest readings of 35C forecast for isolated areas on Friday and Saturday.
On Monday, the highest temperature was recorded as 34C in Teddington, south-west London, the national forecaster said.
Met Office deputy chief forecaster Steven Keates urged people to “take the usual precautions with the heat and the sun”.
He said: “Parts of the UK are entering heatwave conditions: the third heatwave in the UK so far this year.
“However, unlike the May and June heatwaves, we are not expecting this heatwave to be record-breaking.
“Temperatures this week are not expected to reach the highs we witnessed last month, though parts of southern England in particular are likely to see several days in the low 30s, and a few places could reach 34-35C later this week.”
The Met Office also warned England could experience “tropical nights” later this week, where temperatures will not fall below 20C.