The red weather warning issued by the Met Office covers a large part of the region, including Bedfordshire, Buckinghamshire, Essex and Northamptonshire, from 09:00 BST on Wednesday until 21:00 on Thursday.
Meanwhile, the red heat health alert issued by the UK Health Security Agency (UKHSA) will cover the whole of the region.
Met Office deputy chief forecaster Mark Sidaway said its red warnings were reserved for the “most severe events”, and temperatures were expected to reach nearly 40C.
“The last time the UK recorded temperatures this high was in July 2022, but on this occasion the heat is expected to be accompanied by high humidity,” he said.
He added there would be consecutive nights where temperatures did not drop below 20C.
So hot today… Had a freak storm barrel through here too, which was a bit scary.
I was looking at a lighning tracker earlier and Somerset was getting absolutely hammered by 150 lighning strikes a minute which looked mental on the map
Yeah, it was mad. I don’t think I’ve seen anything like it in real life before. A huge lump of cloud like a mountain raced in from the southwest with a weird turquoise area in the back of it. When it got overhead really strong wind suddenly started blasting and there was sideways torrential rain. Because it was so hot I decided to stand in it outside and cool down but had to go back inside because the rain was too hard and I got worried about being hit by lightning. The trees were taking a clobbering as well. It was a spectacle but also kind of monstrous tbh and I hope we don’t get any more of them.
Climate change will bring plenty more.
You’re so lucky, I wish we had a storm to take the pressure edge off.
I was up till half 4 and it was just thunderstorms for over an hour, still going when I fell asleep. I don’t think I’ve seen so much lightning.