A huge swathe of the UK will be rocked by thunderstorms while forecasters predict temperatures to peak at around 27C.
A yellow weather warning has been issued by the Met Office for thunderstorms covering almost the entire length of the UK.
The warning is in force from 9am today until midnight. Forecasters have warned those in the affected areas to expect 'heavy showers and thunderstorms'.
There are further warnings of 'flooding of homes and businesses' along with 'damage to some buildings from floodwater, lightning strikes, hail or strong winds.'
Fast flowing or deep floodwater is possible which could cause 'a danger to life' according to the Met Office. Travel disruption with road closures, cancellations and power cuts is also possible.
The Met Office said: "Heavy showers and thunderstorms are expected on Saturday, during the morning mainly over parts of England before becoming mainly focused over northern England and Scotland by late afternoon/evening.
"Some intense downpours are likely and whilst rainfall accumulations will vary from place to place, as much as 50 mm of rain could fall in a short space of time in some locations. Hail, lightning and gusty winds will be additional hazards."
There is a further yellow weather warning for thunderstorms covering Northern Ireland which is in force from 10am on Sunday to 9pm.
Meanwhile, temperatures are expected to soar for many parts of the country today with highs reaching towards 30C in some regions, peaking at about 27C.
The Met Office has issued a 48-hour heat alert covering the UK this weekend. The forecasters and UK Health and Security Agency (UKHSA), are warning Brits to stay safe in the sun over the next few days.
While the heat burst could be shortlived, vulnerable Brits could suffer some serious health consequences.
Met Office Deputy Chief Meteorologist Dan Harris said a plume of "very warm air" would prompt the heat surge. The six regions covered by the warning include London, South East, East Midlands, West Midlands, East of England and Yorkshire and the Humber.
This Evening and Tonight:
Any rain clearing in the northwest to give a warm dry evening for most, with plenty of late sunshine. Muggy overnight, perhaps giving uncomfortable sleeping conditions. A few showers and thunderstorms arriving in the west later.
Saturday:
Another hot day in the east, but rain and thunderstorms spreading across many areas for a time, especially in north and east during the afternoon. Windy in the northwest.
