The Met Office has revealed when the heatwave is likely to end, bringing some relief as the UK braces for extreme heat later this week.
A red weather Met Office alert stretching from London across to Somerset and Swansea, and up towards Birmingham, is in place until midnight on Thursday.
An amber warning for heat in south east England has also been extended into Saturday until 9pm, as the exceptionally hot weather looks set to linger late into the week.
The forecaster also said it may need to issue further updates on the extreme weather as more details on the conditions become clear.
Grahame Madge, Met Office spokesman, said: “We have issued another amber warning for eastern and central England for Friday.
“As the forecast continues to evolve we may need to issue further updates once more detail becomes clear.”
Temperatures are forecast to exceed 37C and likely rise to 38C or even 40C in some areas over the next few days, and have already caused disruption to schools and transport networks.
Hot and humid nights will also make this heatwave harder to handle. Overnight temperatures will not drop below 20C in urban areas, which is known as a tropical night.
The air is also very humid, making the heat even more impactful. Normally the body cools itself through evaporation, but when it is humid, the air is already saturated with water vapour and it cannot absorb moisture from the skin. This means sweat is unable to evaporate and draw heat away from the body.
Heat health alerts have also been issued by the UK Health Security Agency (UKHSA), warning that this heatwave can pose a risk to even healthy individuals.
Dr Agostinho Sousa, head of extreme events and health protection at UKHSA, said: “A red heat health alert indicates a risk to life for even the healthy population, but simple actions like staying hydrated, avoiding the sun during the hottest part of the day, and keeping your home cool can make a big difference.
“It’s also important to look out for others, especially elderly relatives, neighbours, and those with underlying health conditions, to make sure they are aware of the forecast and following the necessary advice.”
But the muggy nights and blistering daytime heat will start to ease over the weekend, with cooler temperatures expected from Sunday.
Explaining when the heat will start to ease, the Met Office said: “Thursday will see the peak of the heat for many, though those further east will retain extreme heat on Friday and Saturday and could continue to see further impacts, which has resulted in Amber warnings.
“The far southeast will retain the warmth the longest, though there should be a climb-down in figures by Saturday, with peaks around 32C likely.
“Next week is likely to see a change to more of a westerly influence on the UK’s weather, with a return to more average temperatures for the time of year and a mixture of winds and rain, particularly for those in the North West.”
According to the Met Office, temperatures could be 15C cooler by Sunday, with London forecast to see highs of 26C and Cardiff 20C.
