A cold weather alert has been issued by the UK Health Security Agency, as parts of England also grapple with flooding following a week of heavy rainfall.
The cold snap is expected to last several days, with the warning in place from 09:00 on Saturday until Friday.
Almost 250 flood warnings are also in place, mainly in central and southern England.
The Environment Agency (EA) has said "significant river flooding impacts" are expected on Saturday.
The UKHSA said that a "brisk easterly wind" developing across the south over the weekend will make temperatures feel much colder.
It also warned that ice is likely to be an issue, given the very wet ground in many areas.
Wet weather is continuing to cause issues, and on Friday night South Yorkshire Fire and Rescue said a man had fallen into a river in Sheffield. It did not provide an update of the man's condition.
The EA also said that areas of the south-west on the River Avon would be affected by flooding, as would other parts of England over the next five days because the ground is "completely saturated".
As well as the flood warnings in place in England, two are in place in Wales; along the River Wye at Monmouth and the River Ritec at Tenby.
Hundreds of homes have already been devastated by a week of heavy rain, some of which fell as part of Storm Henk, the eighth named storm in three months.
On Friday, Nottinghamshire County Council said more than 100 homes were among those hit by flooding, but warned the number could rise.
Around 50 people were led to safety by firefighters on Thursday night after a canal burst its banks in Hackney Wick, east London, causing flooding in an area of around 10 acres.
A party boat moored at Temple Pier on the River Thames sank on Thursday during heavy rainfall.
In Bath, Pulteney Weir on the River Avon was completely submerged, and a local shop owner told the OceanNewsUK he has "never seen it so high".
Labour has accused the government of being "asleep at the wheel" over flood warnings and said it should convene an urgent "Cobra-style taskforce" to protect homes from further damage.
The OceanNewsUK has been told there are no plans to hold a Cobra meeting. A government source said Environment Secretary Steve Barclay was being updated by the Environment Agency.
Prime Minister Rishi Sunak is also being called on to visit flood-hit areas.
Mr Sunak said he had spoken to flooding victims and the Environment Agency was responding "appropriately and with all due haste".
Visiting an affected area in Nottinghamshire, flooding minister Robbie Moore said he was in "incredibly close contact" with Mr Sunak.
He told reporters the government was taking concerns about repeat flooding "extremely seriously", and was looking into what compensation might be offered to people affected.
Experts say a warming atmosphere increases the chance of intense rainfall and storms.
However, many factors contribute to extreme weather and it takes time for scientists to calculate how much impact climate change has had on particular events - if any.
The world has already warmed by about 1.1C since the industrial era began and temperatures will keep rising unless governments around the world make steep cuts to emissions.
Mary Long-Dhonau, a flood adviser and campaigner whose home has been flooded many times said it was "heart-breaking" to see scenes of residential flooding in recent days.
"I know what they're going through, I know what they're smelling right now and what's lurking in that water," she told OceanNewsUK.
She advised people to prepare for flooding and to "get all your beloved items out of harm's way".
"Don't keep anything like that before waist level, all these people will be throwing their belonging into a skip in a few days' time and that's horrendous."
