Hundreds of people have been evacuated as river levels have risen and in places surged through flood defences while rain continued to wreak havoc across the country.
Householders have already evacuated 900 properties after deluges left many uninhabitable and caused road and rail chaos, and residents were warned to leave another 500 homes in the beleaguered city of St Asaph in North Wales. The EA later issued two severe flood warnings in Wales - one for St Asaph - indicating a potential danger to life.
Though forecasters offered some hope of respite - with rain predicted to ease off - the Environment Agency (EA) warned of a continued flooding threat across north-east England, North Wales and Northamptonshire.
River levels are set to peak in the next 48 hours, putting further properties at risk, with the Thames, Trent and Severn deemed to be of particular concern. Rising groundwater levels are also threatening to leave homes in Winterbourne Abbas, Dorset, under water.
Four people have died since flooding began - including an elderly woman found dead in her flooded home in St Asaph - and the latest figures show around 960 properties have flooded since Wednesday.
John Curtin, of the EA, said: "Environment Agency flood defences have protected some 55,000 homes and our teams are continuing to work around the clock with local emergency services to keep communities safe. People should sign up for free flood warnings, keep up to date with the latest situation on our website, and stay away from dangerous flood water."
The EA has 266 flood alerts and 200 flood warnings in place in England and Wales. There was further disruption for thousands of drivers, while train services were subject to hold-ups in the West Country. The North East also experienced rail problems, with buses having to replace trains on some routes.
Parts of a new £45 million defence scheme in Nottingham - which was opened in September - have been put into action for the first time, while teams have deployed mobile defences to protect properties in Oxford, the EA said. Meanwhile, councils have placed thousands of tonnes of sandbags, water pumps and emergency accommodation at the ready.
Forecasters said the heavy rain would soon abate but with some areas already saturated, any wet weather could still cause problems. Meanwhile, freezing temperatures are expected to take hold of the UK over the next few days, with snow forecast to hit many coastal areas.
Gemma Plumb, a spokeswoman for MeteoGroup, the weather division of the Press Association, said: "Although the rain was lighter last night than previous days, the rain fell on already saturated surfaces adding to the risk of flooding. It will become increasingly drier in most places as we go through today, with just East Anglia and south east England holding on to the rain."