A national
thunderstorm warning is in place after the
Met Office said there is a risk of power cuts, delays and property damage.
Large swathes of
Britain have been hit by storms and lightning strikes as the country braces itself for potentially record-breaking temperatures.
A national thunderstorm warning is in place until 9am on Wednesday after the Met Office said there is a risk of power cuts, travel delays and damage to properties.
With a heatwave gripping much of Western Europe, temperatures in South East England could reach 34C (93.2F) today before rising further to a sweltering 38C (100.4F) on Thursday.
Forecasters are set to reveal this morning if the
UK recorded its highest-ever overnight temperature, with the previous record of 23.9C (75F) set in August 1990.
After temperatures across England exceeded 30C (86F) on Tuesday, forecasters have predicted the UK will record its hottest-ever July day this week - beating the 2003 record of 36.7C (98.1F).
There is also a 40% chance of the UK will set its all-time record high temperature, surpassing 38.5C (101.3F) logged in Faversham in August 2003.
Frank Saunders, chief meteorologist at the Met Office, said: "There is a real possibility of records being broken this week, not only for July but also all-time records.
"The weather setup is broadly similar to the pattern that brought high temperatures to much of continental Europe at the end of June.
"The difference this time is that the wind flow will be more directly from France, paving the way for some exceptional, perhaps record-breaking temperatures.
"As well as high temperatures during the day, overnight temperatures will also be notably warm and could also break records.
"Conditions will feel much more comfortable for western parts of the UK by the time we get to Friday."
Police have issued a warning about the dangers of open waters after a body was found during a search for a swimmer in a Gloucestershire lake, and three people went missing in different stretches of the River Thames.
In Kent, where the temperature soared to 32C (89.2F), more than 100 firefighters worked to control a blaze at a military firing range.
Train company Southeastern said it would be running a "significantly reduced service" on Thursday due to speed restrictions announced by Network Rail.
Temperatures could also hit 35C (95F) further north in Birmingham and Manchester, the Met Office said.
Owen Landeg, from Public Health England, urged Britons to check on older people, young children and those with underlying health conditions who face "real health risks" from the heat.
Forecasters have predicted a record-breaking run across Europe this week, including Belgium, Germany and the Netherlands.
The French city of Bordeaux has seen record-breaking temperatures of 41.2C (106.1F).
A World Meteorological Organisation spokeswoman reportedly said the heatwaves bore "the hallmark of climate change".
In the UK, temperatures are expected to return closer to normal from Friday, with the weather becoming more unsettled with an increased chance of showers.
In contrast to Thursday's temperatures, highs on Friday could be 10C cooler with 27C (80.6F) likely in London, the Met Office said.