South-west England and Wales face gusts of up to 60mph on Sunday while the rest of the UK is also expected to experience strong winds and further downpours.
Forecasters said trees could be brought down and already waterlogged areas could be flooded as up to 40mm of rain was predicted to fall in places. The wet weather is set to continue into next week.
England and Wales have experienced the wettest week since December with forecasters seeing no sign of the rain letting up and supermarkets reporting soaring sales of wellies and umbrellas amid the deluge.
The Environment Agency has warned of localised flooding across parts of the south-west, south-east, Midlands, eastern England and Wales. A spokeswoman said: "The Environment Agency is closely monitoring the forecast and rainfall particularly in Worcestershire, as the river levels are already higher than normal in the rivers Severn, Teme and Avon.
"Environment Agency officers are out monitoring river levels, checking defences and clearing any potential blockages, such as fallen branches and debris, to reduce the risk of flooding. Residents who live near rivers like the Severn should register for the Environment Agency's free flood warnings service and everyone can keep up to date by checking our website, calling our Floodline on 0845 988 1188 and looking out for updates on our Facebook and Twitter pages."
Tom Tobler, a forecaster with MeteoGroup, the weather division of the Press Association, said: "Gusts of 50mph to 60mph are sweeping across south-west England, central England and Wales, which will see the worst of the windy weather. The wind will then spread north-westwards throughout the day with other areas seeing gusts of up to 40mph. There is potential for it to cause some damage.
"The south-east will experience heavy rain this morning, but it will then ease off, with the heaviest rain in the south-west, central England and Wales. It will then spread northwards."
Another band of heavy rain is expected to sweep across Wales, the Midlands, the south-east and East Anglia on Tuesday, but the rain will be more showery in the south-west.
Many of the areas at risk of floods are in a state of drought, particularly in the south-east, East Anglia, the Midlands, the south-west and south and east Yorkshire after two unusually dry winters in a row.
In its latest weekly drought briefing, the Environment Agency said all regions had received above average rainfall for April, boosting river levels and providing relief for farmers, gardeners and wildlife in drought areas.
But groundwater levels remained low and the rain was not yet making a difference to the drought conditions, it warned. And soil affected by prolonged dry weather is increasing the risk of flash floods as heavy rain quickly runs off hard, compacted ground.
Five flood warnings were in place on Sunday for the north-east, with properties at risk from rising water levels in a number of rivers including the Ouse in York. Householders were urged to take action to protect their homes.
The latest downpours come at the end of a particularly wet week for England and Wales, in which 42mm (1.7in) of rain fell in the south-east and 55mm (2.2in) in the south-west, which has had 166% of the average rainfall for April.
More than two dozen properties were flooded in St Helen Auckland, County Durham, on Thursday, while there were localised floods in Devon and Cornwall earlier in the week.
Meanwhile an eight-year-old boy believed to have fallen into a rain-swollen river while playing with friends has been named by police. Ian Bell, from Sunnybrow, Co Durham, is thought to have fallen into the River Wear, near Willington, at around 7pm on Friday.
Police, the fire service, the RAF, mountain rescue teams and police divers have been carrying out a major search operation for the boy.
Janice Larnach, the owner of the Brown Trout pub, near where he is believed to have fallen in, said the boy's brother had told search teams he saw his sibling fall and grab on to a tree branch, which then snapped.
Neighbours have been helping with the search and said his mother had recently given birth to her fourth child.
A Durham police spokesman said: "Ian Thomas Bell, aged eight, was playing with his friends in the area of the Brown Trout pub, which is in close proximity to the River Wear, where it is thought he has fallen into the water.
"Since then, a major search for Ian has been ongoing with assistance from the fire and rescue service, mountain rescue, the Durham county council civil contingency unit and a Northumbria police marine unit, specialising in underwater search and rescue. Police are also keeping in regular contact with Ian's family and updating them as the search continues."
