The Met Office has warned that thunderstorms and severe weather across much of the UK could cause flooding in some areas.
Travel disruption was also a possibilitythe forecaster said. There was a small chance that homes and businesses could be flooded quickly during thundery downpours, with lightning strikes, hail and strong winds expected.
Power cuts and difficult driving conditions were also possible, and 20mm to 30mm (0.8-1.2in) of rain could fall in an hour in some areas.
Met Office severe weather warnings covered swaths of England, Wales and Scotland across Tuesday and Wednesday. The area affected by Tuesday’s warning has been extended, with storms expected to hit more of the country than previously thought.
Calmer conditions are forecast from Thursday, with sunny spells and occasional showers predicted for many.
Belgium, Germany and the Netherlands also broke national heat records last week as hot weather spread across central and western Europe.
Experts warn that global warming caused by human activities such as burning fossil fuels, which are increasing the amount of greenhouse gases in the atmosphere, is making heatwaves more likely and more intense.
Thunderstorms across UK could cause floods and power cuts – The Guardian