It is officially the hottest day of the year so far, with temperatures reaching 30.2C at Hawarden Airport in Wales, weather forecasters said.
The record came a day after the hottest day of the year was declared on Monday, as temperatures reached 29.4C (84F) in St James’s Park, London, according to the Met Office.
Forecasters had earlier predicted Merseyside would beat Monday’s record with temperatures expected to reach 31C or even 32C, but Wales won out around 4pm.
The heatwave is expected to last throughout the week, but temperatures will begin to dip over the weekend with some thundery showers predicted.
But while Brits were seen basking in parks, on benches and beaches throughout the UK today, the warm weather is causing chaos on the railways.
The heatwave has caused tracks to expend, leading to emergency speed restrictions coming into effect. The restriction, is expected to add ten minutes to journeys, and will be in force until Friday.
After delays on Monday, commuters were again bracing themselves for a difficult trip home on Tuesday with South Western Railway announcing that services in and out of Waterloo would be disrupted all week.
Disruptions were also reported on Southeastern trains leaving London Bridge on Tuesday and Cannon Street due to broken down train near Lewisham.
The Bakerloo line is part suspended between Stonebridge Park and Harrow and Wealdstone due to a signal failure at Wembley.