The Met Office has a yellow thunderstorm warning in place across parts of Kent, in south east England, on Thursday morning.
It comes as London mayor Sadiq Khan warned that “parts of London are still flooded or at risk of flooding”, following sudden downpours on Wednesday.
The Environment Agency issued 17 alerts, covering London and parts of the south, stating that “flooding is possible”.
The Met Office warning said there was a small chance of showers continuing to form over the north Kent coast and feed inland overnight into Thursday.
It said: “Where these do occur 30mm of rain is possible in an hour and 40-50 mm in a few hours with the small chance of some disruption.
“Lightning and hail may also be additional hazards.
“The greatest likelihood however is that the showers will remain mostly offshore with limited rainfall inland.”
Possible disruption could include difficult driving conditions and some road closures due to spray and standing water.
Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services, the weather warning adds.
The Met Office said Thursday would be damp in Northern Ireland and western Scotland as rain pushes eastwards, rather cloudy across southeast England and brighter for parts of Wales and central England.
It follows a day where storms brought sudden downpours which flooded some of London’s transport stations and streets, and brought England’s Test match at Lord’s cricket ground against South Africa to an early close.
Some shops and platforms at central London’s busy Victoria Station were forced to close for a period after flooding at the main entrance left large volumes of water running down a slope leading towards the eastern concourse.
The Almeida theatre in Islington, north London, also had to cancel a matinee performance as water leaked through the roof.
Footage from the venue, posted on social media, showed audience members evacuating after the opening hour of Peter Morgan’s new play Patriots.
Gatwick Airport also warned of delays and cancellations to some flights as air traffic control restrictions were imposed across the south of England and parts of Europe due to poor weather conditions.