Storm Bella is due to lash parts of the UK on Boxing Day after dozens were rescued and homes and businesses flooded by heavy rain in the run-up to Christmas.

The Met Office said conditions across the UK will turn increasingly unsettled through to December 27, with strengthening winds and heavy rain moving in from the north.

An amber national severe weather warning has been issued for parts of south Wales and across southern England, with gusts expected to reach up to 60-70mph in exposed coastal locations.

A yellow warning for wind for the whole of England and Wales as well as the far south of Scotland has also been issued and will be in force from 3pm on Boxing Day.

It came as homes and businesses were flooded and dozens of people were rescued from vehicles after heavy rain fell on Wednesday.

A weather warning for rain stretched across large parts of the south and midlands, remaining in place until 2am on Thursday.

But across England, 107 flood warnings and 135 flood alerts were still in force at 7pm on Thursday as huge amounts of water worked its way through river catchments.

On Thursday evening, Northamptonshire Police said the emergency services were preparing to evacuate more than 1,000 people from the Billing Aquadrome holiday park in the county.

The force said the heavy rain had caused flooding with water up to 5ft deep in places.

Emergency accommodation was being sourced for the residents of around 500 caravans, some of whom showed signs of hypothermia.

Chief Superintendent Mick Stamper said it was an “exceptionally challenging situation” and asked residents to leave the site if they could, adding they would be exempt from Covid-19 travel restrictions.

Northamptonshire Fire and Rescue Service previously responded to 250 incidents, deploying crews to pump out properties and stranded vehicles.

Herefordshire and Worcestershire Fire and Rescue Service said it was “deluged” with calls from 3pm on Wednesday, and rescued 44 people from stranded vehicles.

Properties in various parts of the country, including East Anglia and Gloucester, were also flooded as there was up to two inches of rainfall in some areas.

Patrick Lloyd, 27, from Peterborough, Cambridgeshire, told the PA news agency he woke up to find much of his home had been submerged in water, causing thousands of pounds worth of damage.

He added that he had to help rescue an elderly neighbour who had become trapped without power.

Mr Lloyd said the 86-year-old woman had eventually been taken to hospital after spending around 50 minutes in the “freezing” floodwater.

“Luckily a bloke driving by saw her and got out and helped us with her. We had to get the fire service out to get her on to a board and we lifted her out for an ambulance,” he said.

Bedfordshire emergency services said they had 60 999 calls in 90 minutes, including three to people needing to be rescued from cars.

Milton Keynes Council said its staff and Buckinghamshire firefighters had been helping residents in Newport Pagnell, New Bradwell and also Stony Stratford, where the high street had flooded, describing surrounding river levels as “exceptionally high”.

Gloucestershire fire brigade said it had received “hundreds” of phonecalls, with the A40 west of Gloucester to Over, closed due to floodwaters, as police bemoaned motorists “ignoring” road closure signs.

Flood barriers had been put up as a precaution in Ironbridge, Shropshire, as well as Bewdley, Worcestershire, although levels there were not expected to reach those seen in February when the town’s defences were partially breached.

According to a Natural Resources Wales gauge, 60.4mm of rain fell within 13 hours at the Trevethin reservoir in southern Wales on Wednesday.

In Ross-on-Wye, Herefordshire, 50.6mm – more than 2 inches – of rain fell, with 44.6mm of rain also detected in Corby, Northamptonshire, in the same period according to Environment Agency figures.

Meanwhile, in the North East, on Christmas Eve, snow was falling in Newton Aycliffe, County Durham, and Gateshead Tyne & Wear, as well as north of the border in Aberdeenshire, Scotland.