Emergency services are on "high alert" across England and Wales after fresh flood warnings - as police name the man who died in the treacherous conditions.
Jonathan Gammon, 52, was trapped in his car as it was swept away by 5ft of water in Compton Wood, Hampshire, on Monday.
His 55-year-old wife, who is thought to have been driving the car, managed to escape from the vehicle but he was pronounced dead at the scene. Their dog also died.
The Environment Agency now has more than 30 flood warnings in force across the South West, the Midlands, the North East, Anglia and Wales.
People in the affected areas are advised to move to a safe place, turn off gas, electricity and water supplies and put flood protection equipment in place.
The agency has also issued around 115 alerts for potential flooding.
The Met Office warned: "The public should be aware that, following recent heavy rainfall, further localised flooding is possible, with parts of Devon, Dorset and Somerset looking especially vulnerable."
Heavy rain and strong winds across southern Britain and Ireland have brought flooding overnight and dangerous conditions on many roads with extensive surface water.
Forecasters predict there will be more outbreaks of rain today, particularly in the south of England and Wales before it eventually begins to clear.
Police had earlier said they were looking for a man they feared had drowned in flood waters in the River Severn in Tewkesbury after a member of the public heard cries for help early in the morning.
But they later said two people had come forward to say they were in a group
of people shouting despite not needing any assistance.
Met Office figures have confirmed that last month was the wettest April since the first records were taken in 1910.
Data up to April 29 showed an average of 121.8mm had fallen (4.8in) - almost double the long-term average of 69.6mm (2.7in) and beating the previous record of 120.3mm (4.7in) set in 2000.
Sky News weather presenter Isobel Lang said: "Heavy, thundery rain and gusty easterly winds across southern Britain and Ireland will slowly spread north across the Midlands, Wales and into northern England and northern Ireland later - the rain should ease in intensity.
"This will allow southern parts to turn drier and brighter with some warm sunny spells - however one or two showers are still possible."
The Met Office said six of its weather stations had been three times their usual monthly average rainfall in April.
Liscombe in Somerset recorded the highest amount, with 273.8mm (10.8in) compared to its 86.4mm (3.4in) average.
Around 1,000 people had to be evacuated from a caravan park in Great Billing, Northampton, on Monday night due to flooding fears.
Earlier organisers called off the Badminton horse trials - which were due to start on Thursday - because the ground was "totally waterlogged and partially flooded".
Despite the heavy rain, swathes of England are still in a state of drought, with warnings that the downpours were not enough to counteract the effects of two unusually dry winters.
The Environment Agency said all regions had now received above average rainfall for April, boosting river levels - but groundwater levels remained low and the rain was not yet making a difference to the drought conditions.
The agency added that soil affected by prolonged dry weather is increasing the risk of flash floods as heavy rain quickly runs off hard, compacted ground.
Forecasters say the downpours will become less heavy but are expected to continue throughout the week.
Lang said: "There should be less rain generally over the next few days, but still some wet weather is forecast through Wednesday night and Thursday across southeast Britain.
"The north will turn chilly with some showery rain later in the week."