While temperatures may not reach the 40C high experienced last month, Sky News’ Kirsty McCabe said that the extended heatwave will allow for “dangerous levels of heat” with London expected to reach 36C on Saturday and Sunday.
She said: “It’s the duration of the heatwave that will allow dangerous levels of heat to build up, especially in buildings and urban areas.
“The nights will be increasingly warm too, making it difficult to sleep.
"By Thursday lunchtime, parts of the UK had exceeded 30C for four days in a row, and it’s likely somewhere in the UK will be above 30C for at least a week."
A heat dome is when an area of high pressure remains over a region for a number of days, or even weeks.
The dome traps hot air underneath due to high pressure from above which then keeps further warm and dry air at surface levels.
This is expected to create an extended heatwave, which is usually classified as lasting for three days, with London not expected rainfall until Monday at the earliest.
Due to the severe temperatures, the London Fire Brigade reported that it has been called to to 340 grass, rubbish and open land fires so far this month - eight times more than the same period last year.