Thunder and lightning damaged homes and caused travel disruption today as heavy rain left parts of Britain facing flood misery.
The Environment Agency (EA) issued three flood warnings, meaning flooding is expected, and a further 55 flood alerts across England and Wales after a month's worth of rain fell in some places.
It comes after the Met Office issued an "amber" warning of rain for England and eastern and central Wales, as heavy, thundery showers moved northwards during the day.
Up to 30mm of rain fell in an hour in some places, while Westonbirt in Gloucestershire recorded the UK's highest rainfall total of 78.8mm - more than the average monthly amount for July.
The stormy weather caused travel disruption at London's Heathrow Airport as airlines were forced to cancel 20% of flights for a two-hour period.
An airport spokeswoman said earlier: "There is severe weather forecast at Heathrow with a 70% risk of thunderstorms, lightning strikes and hail storms. During thunderstorms the number of aircraft that can take off and land each hour is reduced.
"We have therefore requested that airlines reduce their flight schedule by 20% between 4pm and 6pm. Passengers due to travel on July 19 are urged to check the status of their flight with their airline before travelling to the airport."
Manchester Airport said an electrical surge caused by thunderstorms led to some delays.
General duty manager Gary Brown said: "It impacted on some lifts and baggage systems but most systems are now back up and running ."
A family of four were forced out of their home after their semi-detached bungalow was struck by lightning, Essex Fire and Rescue said.
Firefighters tackled a blaze on the roof of the property in Holland on Sea shortly before 4.30am. No one was hurt.
The roof of another property in Essex collapsed after it was struck by lightning. Three fire crews were called to the house in Murrell Lock, Chelmsford, at about 10.45pm last night after smoke was seen pouring from the roof.
The fire spread to the first floor of the property but there were no reported casualties.
Just after 6am, Essex firefighters were also called to a blaze in a garage at Clacton Road in Elmstead, near Colchester, which was thought to have been started by a lightning strike.
Elsewhere, the first floor and roof of a house in Sittingbourne, Kent, was set alight by lightning, while a bungalow roof was hit in Whitstable, Kent Fire and Rescue said.
Houses were struck in the market village of Lenham, near Maidstone, while lightning also started several small fires in Willesborough, near Ashford.
Patients on a hospital ward had to be moved when heavy rain brought down part of a ceiling. Twenty-seven patients on the cardiology ward at the Royal United Hospital in Bath, Somerset, were transferred after the incident at around 2am.
Three ceiling panels came down in the hospital's catheter lab and cardiology ward after the roof sprang a leak.
The patients, who were unharmed, were taken to other parts of the hospital.
Train services from Bath Spa in the Westbury direction were blocked today due to flooding, First Great Western said.
A number of roads in Gloucestershire were also flooded due to heavy downpours, police said.
Some places avoided the storms, with the UK's highest temperature recorded at St James's Park in central London where the mercury hit 28.8C.
Met Office forecaster Tom Morgan said most of Britain would have a "much better day" tomorrow, although thunderstorms in France were likely to move into East Sussex, Kent and London.
"Large parts of the country should be dry," he said. "Showers will be focused in eastern parts of the country and East Anglia but they won't be as intense as today."
The Met Office has issued a yellow warning for rain tomorrow, urging people to be aware, across eastern parts of the UK.
Three flood warnings were in place - meaning flooding is expected - across the West Midlands. They cover Lyme Brook at Newcastle under Lyme and Trent Vale, the River Chelt at Springbank near Cheltenham, and the Chelt at Uckington and Boddington, near Swindon.
A further 56 flood alerts, meaning flooding is possible, were issued across the Midlands, South East, South West and North East.
John Curtin, director of incident management and resilience at the Environment Agency, said: "Flooding can happen very quickly so we urge people to check local weather forecasts and the Environment Agency website for flood risk information on a regular basis.
"We have already seen rainfall totals of 60mm in some places during Saturday, including in Bradford-upon-Avon and at Westonbirt, near Chippenham.
"We will continue monitoring the situation closely and supporting local authorities, who will respond to any reports of surface water flooding.
"Surface water flooding can happen very quickly depending on where thunderstorms occur, the amount and intensity of the rainfall and the local drainage network. It is possible that roads may quickly become impassable and people are urged not to drive through flood water."
The EA said teams have been clearing debris from streams and unblocking culverts to reduce the risk of flooding.
The area at risk of localised surface water flooding tomorrow has widened to include Greater London, East Sussex, Thurrock and Kent including Medway. There is the risk of flash flooding from small and urban rivers in some of these areas, the EA said.