Much of the UK has been bathed in sunshine with the capital’s parks packed with people soaking up the rays before the close of summer.
Some headed to the banks of the Thames in an attempt to top up their tans before autumn.
But heavy rain and thunderstorms are due to hit the west before sweeping across other areas while temperatures will return to more seasonal norms of around 20C.
Watch: People across the UK soak up the September sunshine
Dan Stroud, Meteorologist at the Met Office said on Wednesday: “It is coming to an end. The breakdown is actually happening as we speak. Thunderstorms have moved over Devon this morning, and that formation is going to move north and east, so we’ll start to see batches of heavy rain and thunder, which will returns us to more seasonal weather.
“By Saturday or Sunday, we’re looking towards regular temperatures in the 20s, back to normal. That’s about what we’d expect to see for early and mid-September.”
He added the high temperatures this week were not entirely unusual.
He said: “We had a 31.3C day in 2016, 31.4C in 2020. We have had these temperatures in the recent years.”
The forecaster said there was a risk of homes and businesses being flooded quickly as well as lightning strikes and hail to hitting the area.
There is also a risk of power cuts as well as difficult driving conditions and road closures, they warned.
Two warnings have been issued, one for Wednesday from 11am until 9pm covering most of south west England and the south coast of Wales.
Another warning on Thursday covers Northern Ireland, Wales and most of northern and central England between 11am and 8pm.
Watch: Three-day weather forecast: How long will September heatwave last?