The Met Office has issued a rare amber warning alert for thunderstorms across parts of England.
Forecasters said that active thunderstorms will bring heavy rainfall, lightning, strong winds, and hail. The warning has been issued from 3.21pm until 7pm.
Due to severe weather conditions, travel disruption and road closures are likely - and some communities in the Midlands risk becoming cut off.
The Met Office added that flooding of homes and businesses is likely and could happen quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.
Forecasters said: "A cluster or line of very active thunderstorms is moving towards the northwest from Bedfordshire and Buckinghamshire towards the West Midlands.
"These will bring a period of exceptionally heavy rainfall with 30-40mm falling in around 30 minutes, perhaps around 60mm in an hour for some locations.
"Frequent lightning strikes, winds that may gust to 45 mph, and some large hail stones perhaps up to 4cm in diameter will also accompany the storms.
"Surface water flooding may happen very quickly, likely disrupting travel and flooding some properties (especially in urban areas).
"Lightning, strong winds and hail will all pose a significant danger to those outdoors. The ultimate northwestern extent of this area remains somewhat uncertain."
The warning comes after the Environment Agency issued 14 flood alerts across the Midlands over concerns heavy, thundery showers could cause large amounts of surface water.
Flash flooding can occur in a few minutes, caused by these highly localised weather conditions.
Urban areas with lots of concrete can be vulnerable to flash flooding as the rain hits surfaces such as pavements which cannot absorb heavy downpours, leaving them to flow into drains or roads.
Underpasses can also fill quickly and drivers could face hazards with flood water on roads.
Yesterday, people were trapped in submerged cars after thunderstorms flooded lanes on motorways and on major roads in Manchester.
Higher temperatures are concentrated in the north today, with Manchester, Leeds, and Keswick, Cumbria, between 30 and 31C, while south-central England remains in the high 20s, with London and Cambridge both reaching between 27 and 28C.
Further thunderstorms may be possible in the first half of the week, with fresher conditions and temperatures slightly decreasing towards Thursday and Friday.
However, the sunny weather is staying with most parts of the country forecast to remain above 24 and 25C throughout the week, and temperatures potentially reaching 29C in Bristol and Birmingham over Wednesday and Thursday.
Cooler air from the North Sea will reach parts of the UK on Thursday and Friday, particularly areas along the North Sea coast and the East of England.
UK 5 day weather forecast
Today:
Staying hot and humid for many on Monday, with plenty of sunny spells developing. Scattered slow moving thundery showers will develop during the day. Feeling very warm but cooler near eastern coasts.
Tonight:
Thundery showers will ease through the evening with most places becoming dry overnight. It will remain warm and muggy for many, especially in the south.
Tuesday:
Another very warm and muggy day, some showers, possibly thundery, are likely in the west. Most places dry with sunny spells. Feeling a little fresher along eastern coasts.
Outlook for Wednesday to Friday:
As high pressure builds, it will turn more settled with plenty of dry weather and long periods of warm sunshine on offer. Feeling much fresher than of late.
