The Met Office has yellow severe weather warnings of heavy rain in place for Yorkshire and the Humber, as well as Wales, the West Midlands, the East Midlands, the east of England, the South West and South East.
The Environment Agency has issued a flood warning for Whiston Brook, near Rotherham, and 32 more across the country, indicating flooding is expected and immediate action is required.
Today’s forecast for Yorkshire predicts patchy mist and fog with further heavy showers developing inland and turning thundery, especially over the Pennines. Winds still light.
Friday afternoon will see a more persistent band of rain, heavy at times, moving southwards along the east coast.
Councils across England and Wales are highlighting the danger to residents and businesses of flash floods, which can see local areas swamped in minutes after deluges.
The move comes amid concerns the UK’s weather is becoming more volatile as a result of climate change, with more heavy downpours that cause rapid flooding.
The Local Government Association (LGA), which represents English and Welsh councils, said homeowners and businesses at risk of flash floods should regularly check weather forecasts and know how to turn off gas, electricity and water.
They should also have a plan for moving essential items upstairs quickly, the LGA said.
It is also warning people they should never try and walk or drive through floodwater, as it only takes 15cm (6 inches) of fast-flowing water to knock an adult off their feet, and just 60cm (2ft) to sweep away a 4X4 car or small lorry.
Town halls also want the Government to bring in mandatory anti-flood measures for new homes in building regulations, including raised electrical sockets, fuse boxes, controls and wiring above floor level, ventilation brick covers, sealed floors and raised damp-proof courses.
New flood defence funding should be devolved by the Government to local areas, so that councils can work with communities and businesses to ensure money is directed towards the best projects for the area, the LGA has urged.
Peter Box, LGA environment spokesman, said: “Flash floods can bring devastation to communities within a matter of minutes, causing enormous disruption to families and businesses.
“Councils up and down the country have been doing everything they can to prepare for heavy rainfalls this week by launching awareness campaigns to highlight the dangers.
“They are also working closely with emergency services, such as the police and firefighters, to minimise disruption to residents and businesses and help protect communities.”
The latest warnings come after flash floods hit Cheshire earlier this month, and cars were left submerged and motorists forced to escape sudden deep flooding in south London.
Earlier this week, Heartlands Hospital in Birmingham declared a major incident after flooding in the Emergency Department. Parts of the Bullring, the city’s major shopping centre, also had to be closed because of flooding.