Flood-hit communities are facing days of more misery as heavy rain and storms look set to cause further significant flooding.
A triple threat from the elements, with warnings in place for heavy rainfall, gale-force winds and snow, will pile on the problems for areas already struggling in the wake of a string of wild winter storms.
More than 1,000 homes have been evacuated in the Thames Valley and the West Country, and others have been left without electricity.
Ongoing flooding could continue to affect homes, businesses and land for at least another week, the Environment Agency said.
The agency has 17 severe flood warnings - meaning risk to life - in force along the River Thames, the Severn at Gloucester and on the Somerset Levels, and hundreds more flood warnings across England and Wales.
Windsor, Maidenhead, parts of Surrey and communities in Buckinghamshire, West Berkshire and Reading are at risk from the River Thames, which has seen levels rise to 60-year highs, and significant flooding is expected.
Severe gales, large waves and high sea levels are threatening coastal flooding on the Dorset coast, while the south coast from Cornwall to East Sussex is also at an increased risk, the Environment Agency said.
And with further rainfall expected today and Saturday, communities are also facing flooding in the south west of England, along the Stour and Medway in Kent and along the River Severn in Gloucestershire and Worcestershire.
Saturated ground could lead to flooding around Croydon, Hambledon, Basingstoke and Lower Farringdon in Hampshire.
Paul Leinster, chief executive of the Environment Agency (EA), said: "As a result of the exceptional weather, the risk of flooding continues, especially along large rivers like the Thames and Severn and in Somerset.
"People should remain vigilant and take action where necessary. Flood water can be dirty and dangerous and people are advised not to walk, drive or play in it.
"With further rainfall today and into the weekend, river levels are expected to rise again."
More temporary flood defences are being deployed across the Thames Valley, including at Chertsey in Surrey to protect up to 200 homes and at Staines in Berkshire, to protect around 150 homes.
The military has come to the aid of the most vulnerable as the crisis has deepened, with transport links disrupted and whole streets cut off as flood water rises to waist level in the worst-affected areas.
The Duke of Cambridge and his brother Prince Harry joined colleagues from the armed forces in helping with the supply of sandbags to defend Datchet, Berkshire.
The Queen has even shown her support for Somerset farmers affected by the flooding on the Somerset Levels by contributing feed and bedding from the royal farms at Windsor, a spokesman for Buckingham Palace said.
And the EA confirmed it had suspended plans to axe hundreds of jobs, as staff battle the elements alongside emergency services and local authorities.
Mr Leinster emailed staff saying: "We are reviewing the timetable for the change programme... We will not be seeking any further engagement with staff on ways of working during this period and will not be entering into any formal consultation arrangements."
But Justin Bowden, national officer of the GMB union, said: "While EA has put consultation on redundancies on hold this statement makes clear that they will press on with redundancies after the floods have receded."
The crisis is far from over, as the Met Office predicted a return to the worst of the winter weather over the next 24 hours, with almost every pocket of the UK experiencing downpours, winds or snow, much of it falling on already-saturated ground.
Charles Powell, meteorologist with the Met Office, said: "It's going to be bad, no question about it.
"There will be a big band of rain starting in the South West and moving up, some strong winds of up to 80mph in some exposed areas of the south coast, and even snowfall predicted. The only thing we haven't got is the fog."
He said up to 40mm (1.6ins) of rain could fall in the South West today, before it heads north towards Scotland.
He said few places would get through to tomorrow afternoon without experiencing poor weather.
Prime Minister David Cameron said he is "very sorry" for the suffering caused by the extreme weather afflicting large swathes of the country.
Visiting Blackpool in Lancashire to view relief efforts, Mr Cameron told ITV1's Daybreak: "People need to be reassured that we will do whatever it takes to help people during this very difficult time."
"Obviously, we are facing a very difficult time because we have got the wettest start to the year for 250 years and these are extraordinary weather events, but we are fighting on every front to help people," he said.
"We are making sure that today, before the next rise in the level of the Thames over the weekend, we do everything we can to protect more homes and protect more communities."
Mr Cameron acknowledged that the extreme weather will have an impact on the UK's economy as it recovers from the downturn, and repeated his pledge that "money is no object" in the relief effort.
But Matt Wrack, leader of the Fire Brigades Union, who is visiting flood-hit areas in the South West, said fire-fighters involved in the response to the disaster were reporting shortages of manpower and equipment because of spending cuts.
Since early December, 5,800 properties have been flooded across the country, with high winds causing further problems yesterday.
Environment Agency regional director Howard Davidson denied that measures to protect urban areas from floods had shifted the problem on to people in the countryside.
Mr Davidson said: "The continued investment programme by ourselves and our predecessors is protecting millions of people from flooding. Whenever we design a scheme, we make sure we do not compromise anybody else's position."
The Environment Agency's staff, emergency services and local authorities deserve "full support and admiration" for their work to tackle the floods and bad weather, the South West Regional Flood and Coastal Committee said.
Leading economist and climate expert Lord Stern has said the record rainfall and storm surges the UK had experienced were a "clear sign" the country was already experiencing the impacts of climate change.
Climate impacts were being felt around the world, from record-breaking temperatures in Australia to floods and landslides in Brazil following record rainfall and Typhoon Haiyan in the Philippines, Lord Stern wrote in the Guardian newspaper.
"This is a pattern of global change it would be very unwise to ignore," he argued, adding that the risks could only be sensibly managed by reducing greenhouse gas emissions - which would require a new low-carbon industrial revolution.
And the Government needed to make the country more resilient to the impacts of climate change, but must also resist calls to cut overseas aid to fund it, he said, as it would be "deeply immoral" to penalise the 1.2 billion people living in extreme poverty around the world.
Firefighters on the Somerset Levels are asking parents to keep children away from flood water.
With heavy rainfall set to continue throughout the weekend and into next week, there is likely to be standing water in many locations while water levels on the Levels will remain high.
Officers working as part of the multi-agency operation on the Levels are concerned by the additional risks posed to children while they are not at school during half-term next week.
Station manager Kevin Hardwill, of Devon and Somerset Fire and Rescue Service, said: "Unsupervised children and water do not mix.
"The added interest of the flooding on the Somerset Levels could lead to children exploring in areas which could put them in danger.
"We would ask parents to warn their children of the risks and to keep them away from flood water."