The latest storm to hit the UK is causing disruption for many people returning to work after the Christmas holidays.
Roads have been closed and train services are cancelled or delayed in some areas because of the weather.
Waves of up to 27ft have been recorded at Land's End - the most southern tip of the UK - with forecasters warning that coastal areas could see more flooding as the heavy rain and gusts of wind continue to batter Britain.
In Aberystwyth, Ceredigion, seafront properties along the promenade were again evacuated to a rest centre at a local school, and across the UK dozens of flood warnings, including one severe, remain in place.
The highest level of warning, indicating danger to life and property, was issued by the Environment Agency (EA) for the Lower Stour in Dorset.
Western and southern areas are bearing the brunt of the latest severe weather, with large waves hitting coastlines throughout Devon, Cornwall and Wales.
The EA issued one severe flood warning for Iford Bridge Home Park near Christchurch, Dorset, meaning "there is significant risk to life".
There are also 105 flood warnings where flooding is "expected" across almost every region in England and Wales, and 219 flood alerts in force.
The Met Office issued a "be aware" yellow warning for wind as gusts of up to 70mph are expected on the west and south west coast of Britain and the east coast of Northern Ireland.
It said bands of heavy showers would continue to move eastwards across parts of the UK and will be accompanied by squally winds, along with hail and thunder.
Some 0.2 to 0.4 inches of rain could occur in less than an hour with, locally, 0.6 to one inch of rain through today and perhaps as much as 1.5 inches on high ground.
"The public should be aware of the potential for localised flooding leading to difficult driving conditions, with hail providing an additional hazard," a Met Office spokesman said.
Northern Ireland has largely escaped any serious flooding or damage but, amid fears of changeable conditions, police announced plans to hand out sandbags in a number of towns close to the Co Down coast, which they believe could be vulnerable to the high tides, wind and rain.
The EA has estimated that around 220 properties have been flooded so far but more than 205,000 properties have been protected as miles of coastline have been battered.
Communities in Dorset and Oxfordshire should remain prepared for "significant flooding" in the lower reaches of the Thames, Dorset Stour and Frome rivers, the EA said.
Continuing flooding is expected on the Somerset Levels and rivers, including the Severn, remain "very high" after recent rainfall.
The transport network has also been hit, with roads closed and trains delayed or cancelled in many areas.
First Great Western warned passengers that there was a risk to services in Cornwall, Devon, Somerset, Wiltshire and Dorset.
The Thames Barrier was in operation last night to protect people and property along the river.
Three people have already died in the storms.
In Oxford a 47-year-old man died when his mobility scooter fell from a flooded path into a river.
A 27-year-old man from Surrey was found on Porthleven Sands beach in Cornwall after he was swept out to sea on New Year's Eve night, and a woman died after being rescued from the sea in Croyde Bay, north Devon.
Meanwhile, searches are continuing in south Devon for missing 18-year-old university student Harry Martin, who was last seen leaving his home to take photographs of the weather - with more than 100 people volunteering to look for him.
Officials around the country have pleaded with people to keep away as dozens put their lives at risk by going to coastal areas to watch as the storm brought waves of up to 40ft high crashing on to land.
A man and child were almost swept away by a huge wave at Mullion Cove in Cornwall as they peered over the sea wall to watch the raging sea and elsewhere in Cornwall vehicles driving on a coastal road were swamped and almost washed away by a tidal surge.
Police pulled a man from the sea who had been drinking at Towan Beach, Newquay, after he ignored warnings about the fierce storms.
In Aberystwyth, a man was rescued by lifeboat after he became trapped when photographing waves from a harbour jetty.
Yesterday, a homeowner was rescued after 13 days stranded in her flooded property.
Anne-Marie Simpson had been cut off since a river near her property at North Curry on the Somerset Levels burst its banks when an initial wave of storms swept Britain on December 23.
She moved upstairs, stockpiled dry food and decided to "wait it out" until the water level receded but after the situation worsened, members of the Burnham Area Rescue Boat (BARB) rescued Mrs Simpson and her dog Elvis.
Jonathan Day, flood risk manager at the Environment Agency, warned that the risk of flooding continues this week.
He said: "Although high tides are now falling, there remains a risk of coastal flooding, especially on the south and west coasts.
"In addition, wet conditions have left the ground saturated in many areas, increasing the risk of river and surface water flooding.
"We would urge people to be prepared by checking their flood risk, signing up to free flood warnings and keeping an eye on the latest flood updates via the EA website and Twitter.
"Environment Agency teams remain out on the ground across the country and will continue to work around the clock to protect communities at risk."
Yesterday, David Cameron pledged that lessons would be learned from the flooding and insisted that the EA has been given the funding to protect frontline services.
Environment Secretary Owen Paterson is chairing a meeting of the Government's Cobra emergencies committee to discuss the latest situation. He will make a Commons statement at 3.30pm.