A powerful summer storm is threatening to bring flooding to parts of the UK this weekend.
The Met Office has issued severe weather alerts for rain covering most of England and Wales on Saturday.
Torrential downpours, lightning, hail and strong gusts could sweep in a day after temperatures are forecast to reach the 30C mark, with Friday tipped to be the hottest day of the year so far.
Yellow "be aware" alerts for rain have been put in place for north-west England, north-east England, Yorkshire and Humber, West Midlands, East Midlands, East of England, south-west England, London and the South East and parts of Wales.
The Met Office said: " Areas of heavy, thundery showers may develop over England and Wales from early on Saturday before moving northwards during the day.
"The development of these is uncertain but where they do form some torrential downpours are possible with frequent lightning, hail and locally strong gusts.
"Significant flooding is possible where these do occur from surface water as well as small, fast responding watercourses.
"The frequent lightning, hail and strong gusts could also be an additional hazard. The public should be aware of the risk of disruption from any of these elements."
The stormy conditions will dampen the mood during what is likely to be the warmest spell of the year so far.
Temperatures will start to rise from Thursday, peaking on Friday when the 30C barrier could be reached for the first time this year, with the most likely location somewhere to the north-west of London.
Forecasts suggest Britain will be slightly warmer than European holiday destinations such as Barcelona, Ibiza and Nice.
The hottest day so far this year was July 4, when 28.7C (83.7F) was detected in Norfolk and Essex.
Met Office forecaster Helen Roberts said most places in England and Wales will feel hot and humid, with temperatures generally around or higher than the 25C (77F) mark.
"Most people won't enjoy these conditions," said Ms Roberts. "It can be difficult sleeping during the hot humid nights.
"Although it probably is shorts and T-shirt weather, you will need a brolly at the same time."