The Met Office has warned parts of Britain could see snow showers as soon as Monday morning amid warnings over sub-zero temperatures.

Forecasters have said the white stuff could fall over high-lying parts of northern England and Scotland overnight, while people in southern England could wake up to falling powder in the morning.

A cold snap, brought by freezing air moving south west from Scandinavia, is set to send the mercury plummeting as low as -4C tonight.

The authorities have issued an amber cold health alert, warning that the sub-zero temperatures could put people at risk and stretch health and ambulance services.

It comes as the Met Office issued a yellow weather warning for ice on Monday across London and the south east from 4am to 10am with a forecast of ‘temperatures near zero’ later on Sunday.

This weather map shows the probability of snow falling in Britain at by 6pm on Monday, with southern and eastern parts of England being most likely to see a sprinkling of the white stuff 

The Met Office has issued a yellow weather warning for ice across parts of Kent, Sussex and London for Monday morning

A snow plough clears snow near the Lecht Ski Centre in Scotland, on December 28

Flooded gardens and homes of residents of the Queen’s road and Hills Meadow area in Reading, Berkshire today

Aerial view of flooded land close to Salisbury Cathedral, Sailisbury, Wiltshire, this morning

This weather map shows areas that are likely to have snow cover by 5am on Tuesday morning with southern parts of England, and northern Scotland most likely

The yellow warning states that snow and ice are likely to affect roads and train services in parts of Greater London, Kent, Surrey, East Sussex and West Sussex.

The Met Office forecast for the UK this evening and tonight says: ‘Some wintry showers near coastal areas and across the southeast but otherwise a dry night with variable amounts of cloud. Fog patches returning, most likely across Northern Ireland, Scotland and northwest England. Widespread frost and icy stretches.’

For tomorrow it says: ‘Fine for many with sunny spells, best of these in the west after fog clears. Scattered sleet and snow showers across southern areas. Wind chill for England and Wales.’ 

For the south west of England, the forecast for this evening says: ‘A cold night with a widespread frost developing and some icy patches. Turning breezier on coasts exposed to the freshening easterly breeze. Minimum temperature -4 °C.’

The forecast for that region tomorrow says: ‘Generally dry with sunny spells, but a few sleet or snow flurries are possible, mainly in eastern counties, but perhaps more widely later. Feeling cold in the brisk easterly winds. Maximum temperature 5 °C.’

It adds: ‘Sleet and snow flurries are possible on Monday night, clearing west Cornwall on Tuesday, then mostly sunny on Tuesday and Wednesday. Somewhat cloudier on Thursday. Often windy and feeling cold.’

Areas in the south of England and northern parts of Scotland are the most likely to have snow cover by 5am on Tuesday morning. 

The amber cold health alert (CHA) for the north west of England, West Midlands, East Midlands and south west of England, issued by the UK Health Security Agency (UKHSA) and the Met Office, runs until 12pm on Friday.

An amber alert means ‘cold weather impacts are likely to be felt across the whole health service for an extended period of time’.

There is also a yellow cold health alert in place for the north east of England, Yorkshire and the Humber, the east of England, the south east of England and London.

Dr Agostinho Sousa, head of extreme events and health protection at UKHSA, said: ‘With the Met Office forecasting drops in temperature across the United Kingdom into next week, it is important to check in on the wellbeing of those most vulnerable to the cold.’

A resident from Queens Road in Reading removing water from inside their house on Sunday

Cars drive along flooded land in Pulborough, West Sussex on Saturday after the River Arun burst its banks in the aftermath of Storm Henk 

A street flooded by the River Ouse after it burst its banks, in central York, on Saturday following Storm Henk, which brought strong winds and heavy rain across much of the country

Flooding in Marlborough, Wiltshire on Friday

He noted that the cold weather can increase the risks of heart attacks, strokes and chest infections and can have a serious health impact for older people and those with pre-existing health conditions.

Dr Sousa added: ‘Temperatures are expected to turn particularly cold overnight, as we would expect at this time of year.

‘If you have a pre-existing medical condition or are over the age of 65 it is important to try and heat the rooms where you spend most of your time, such as your living room or bedroom, in the coming days.’

Many regions are also still trying to cope with flooding following heavy rainfall in recent days.

Nearly 2,000 homes have been flooded over the last few days and that number could rise as water which was dumped on higher ground makes its way downstream in Britain’s waterways. 

Prolonged wet weather, including a deluge of rain from Storm Henk on already sodden ground, has seen some rivers reach near-record levels and there is set to be no let up for those whose properties are at risk. 

By Sunday lunchtime, the Environment Agency (EA) said there were 172 flood warnings and 176 flood alerts in England.

Katharine Smith, flood duty manager at the Environment Agency, said on Saturday: ‘Significant river flooding impacts are still expected… over the next few days across parts of the River Thames in Oxfordshire as well as the River Trent near Nottingham, and the River Severn, including Gloucester. 

‘The prolonged wet weather and intense rainfall has led to flooding impacts and our thoughts are with all of those affected.’ 

Prime Minister Rishi Sunak said ‘flooding has been having a devastating impact on communities up and down the country’ as he spoke to affected residents in Oxford on their doorsteps before visiting EA workers at their depot on Osney Island.

Addressing the media in front of the fast-moving River Thames, Mr Sunak said: ‘I was in the East Midlands last week on Thursday and I’m in Oxfordshire here today talking to some of those that have been affected, but also saying thank you to our first responders who were doing a fantastic job over the past week.

‘We have over 1,000 Environment Agency personnel on the ground in local communities helping, over 200 pumps have been deployed.

‘We’ve invested £5.2 billion in flood defences over the period in question, that’s a record sum, far more than we’ve done, in the future that’s contributed to protecting over 300,000 homes.

‘And of course, there have been many people affected by what’s happened over the past week, but also over 49,000 have been affected by flooding.’

The EA has previously warned that more properties may be flooded in the coming days amid increased river levels and more rain.

Prime Minister Rishi Sunak speaks to members of the Environment Agency on Sunday as he visits flood defences in Oxford

Kayakers watch cars driving through floodwater in Pulborough, West Sussex, on Saturday

A woman wades through the water carrying her dog at Thames Ditton Island near Kingston Upon Thames on Saturday

A man paddles his small boat through the floodwaters in front of a house in Maisemore, Gloucestershire on Friday

A narrowboat lays on its side across the front of a road bridge over the River Soar in Barrow upon Soar, Leicestershire on Saturday

A Mini Cooper driver attempts to get through floodwater in Chertsey, Surrey on Saturday

Vehicles drive through flood waters near Reading Station in Berkshire on Saturday

Submerged cars sit in a car park after heavy rains and sewer system overflows in Wallingford, Oxfordshire on Friday

An Environment Agency worker wearing waders walks along the flooded Thames Footpath in Cookham, Berkshire on Saturday

Labour has accused the Government of being ‘asleep at the wheel’ over flood warnings with leader Sir Keir Starmer vowing to make flood defences ‘fit for purpose’, writing on social media that ‘people’s lives shouldn’t be upended by extreme rain’.

More than 1,800 properties have already flooded after prolonged wet weather and intense rainfall, the agency said, with the impact of high water levels likely to continue, particularly around the rivers Trent, Severn and Thames.

The agency said buildings ‘will flood and there will be travel disruption’ during that time period, and local groundwater flooding is also possible in the south of England, Yorkshire and the Humber.

Forecasters have also said that slower journeys could be faced by people in parts of southeast England, who should be braced for ice across the region on Monday.

The Met Office yellow weather warning states: ‘A mix of sleet and snow showers will move in from the east later on Sunday night along with temperatures near zero.

‘Given these wintry showers, and also wet surfaces after recent wet weather, some icy patches are likely on untreated surfaces.

‘Additionally a few of the snow showers could turn quite heavy; these probably only affecting a narrow zone but a few places could see 1-3cm, mainly over the north Downs and on grassy surfaces.’