Snow and ice have caused travel chaos with four inches of the white stuff forecast as an Arctic blast grips the UK.
Freezing fog blanketed large parts of the nation this morning with Britain colder than Iceland.
Temperatures plummeted to -10C in some areas overnight with the Met Office issuing a series of snow and ice warnings.
Many passengers have taken to social media to vent their frustration as airlines had to delay or cancel flights because of severe weather conditions.
Alex Barnett, who was travelling from London Stansted to Nuremberg in Germany this morning, told The Mirror his flight faced a two-hour delay due to de-icing at the airport.
He said passengers sat in the plane which was stuck on the tarmac for two hours as the airport "took ages" to get the deicer truck out to the aircraft.
Mr Barnett said: "Temperature here is about -2C, they took ages to get the deicer truck out to us.
"We were supposed to take off at 8.20am, still sat on the tarmac at the moment. So that is a two-hour delay."
The passenger said he could see many other planes stuck on the tarmac and none of them were moving.
Stansted Airport told The Mirror flights are experiencing some delays due to freezing weather conditions, but added the airport remains "fully open and operational".
Ryanair apologised to customers and said it is doing all it can to minimise the disruption.
Another passenger wrote on Twitter that there was only one machine to de-ice planes at Gatwick Airport.
She said her plane will face a delay of at least three hours, adding: "Thanks @gatwick_airport for ruining my birthday (and a Sunday).
"Only one machine to de-ice planes in this weather (-6°), other flights departing on time or reasonably delayed, but mine will be at least over 3 hours. Should be having a bday lunch but instead, THIS."
Sally-Anne Watts tweeted a photo showing long queues at Heathrow Airport and claiming "no one is talking to us or helping" amid flight delays and cancellations.
At Heathrow, at least 48 flights were cancelled on Sunday morning, with Brits reporting "huge queues" at the London airport.
A multiple vehicle crash was also reported along the M4 towards Heathrow Airport, creating 20-minute delays.
Heathrow said a small number of flights were cancelled due to poor weather conditions and visibility and safety of passengers and colleagues remains its number one priority.
A British Airways passenger said a flight meant to depart at 7.25am got delayed until 8.45am and then passengers were told they wouldn't take off until 11.20am.
They added: "This means the connecting flight departing transit point is guaranteed to be missed. I don’t know if its a norm for your weekend flights but this is one too many that I have either experienced or know someone to have."
British Airways told The Mirror that freezing fog at Heathrow and Gatwick has resulted in Air Traffic Control restrictions on the number of flights that can land and depart per hour.
The airline added it is using larger aircraft, where possible, to minimise disruption and ensure as many passengers as possible can travel.
Yesterday, at least 11 flights were cancelled and eight flights diverted at Manchester Airport with both runways temporarily shut due to snow.
Passengers were urged to check the status of flights with their airline.
A spokesperson for the airport told The Mirror it had been forced into the drastic action due to health and safety protocols and "operations will resume at the earliest opportunity".
It comes as the Met Office issued multiple yellow weather warnings for fog, snow and ice across the UK.
Warnings are in force across London and the South East, the South West, parts of the Midlands, the North West of England, Wales as well as most of Scotland.
A warning was issued for Northern Ireland too earlier today but is no longer in force.
In the afternoon, the Met Office also issued another yellow warning for ice and fog covering the North East of England.
It is in force from 4pm today until 11am tomorrow, with freezing fog likely to reduce visibility 50-100 metres at times, as well as create patchy ice on untreated surfaces.
Residents have been warned they may face delays on the road and travel disruption due to icy stretches.
Some communities may also become cut off and face power cuts amid heavy snowfalls.
Up to four inches of snow is expected to fall with wintry showers heading towards Kent, Essex and London later today.
Met Office meteorologist Ellie Wilson said: "It's looking to stay quite chilly through next week with frost overnight and some cold temperatures in the day as well.
"Through Sunday morning, most wintry showers are going to be focused on northern parts of the UK - so Scotland - and the south west of England."
She added: "Through Sunday and into Monday, there's a chance the south east of England could see a little bit more in the way of snow although there's a little bit of uncertainty there.
"There could also possibly be the odd flurry in the south Midlands - the Bristol/Bath area - but anything settling will likely be above 200-300 metres."
Parts of Scotland may see temperatures plummet to -10C overnight, the Met Office said, as the cold weather is set to continue into next week.
Ms Wilson added: "We're expecting it to last at least through next week.
"There's a chance that temperatures could fluctuate a little bit but we're not expecting them to become much milder than we've seen recently with overnight frost expected until at least next Friday, even into the weekend."
While the Met Office has not clarified what the weather will be like over Christmas, The Weather Company said Northern England and Scotland could face up to 30 more days of snow or ice disruption this winter.
Leon Brown, head of meteorological operations at The Weather Company’s Weather Channel arm, said: "More snow and ice than average are expected this winter due to the cold Arctic pattern setting up so early in December.
"Northern England and Scotland are forecast 25 to 30 further days with snow or ice causing disruption, with another 10 or 15 days with impacts now in December, 10 in January and around five in February.
"The South is also expected to see a higher-than-normal number of days of winter disruption, with another 20 to 25 days of snow and ice causing issues.
"Cold polar air is covering the entire country already, and the South is far more at risk of snow as it will be the battleground for moist milder air returning, which can see snow."
The severe conditions have been causing travel disruption with Manchester Airport temporarily closing both runways on Saturday morning due to "heavy snow".
The RAC and North West Motorway Police both issued warnings about driving in the wintry conditions as the latter responded to traffic accidents on several major roads.
The Met Office said the conditions could lead to more travel disruption, especially on Monday morning, and a small chance of some rural communities becoming cut off along with a possibility of power cuts and mobile phone coverage being affected.
Elsewhere, the UK Health Security Agency (UKHSA) sent out a level three cold weather alert covering England until Friday, keeping extended the alert from Monday.
The agency is advising people to look out for friends and family who are vulnerable in the cold and to ensure they have access to warm food and drinks, adding that people should maintain indoor temperatures of at least 18C (64.4F).
Dr Agostinho Sousa, consultant in public health medicine at UKHSA, said: "Cold weather can have serious consequences for health, and older people and those with heart or lung conditions can be particularly at risk.
"If you have a pre-existing medical condition, you should heat your home to a temperature that is comfortable for you.
"In rooms you mostly use such as the living room or bedroom, try to heat them to at least 18C if you can. Keep your bedroom windows closed at night. Wearing several layers of clothing will keep you warmer than one thicker layer."
Darren Clark, severe weather resilience manager at National Highways, said gritters would be out to keep motorways and major A-roads open.
He said: "National Highways is committed to treating every road which needs to be treated - whenever it is needed."
Amid travel delays and cancellations, Stansted Airport said in a statement: "Flights from London Stansted are experiencing some delays due to current freezing weather conditions and the need to de-ice aircraft prior to departure.
"We are working closely with airline and ground handling partners who are responsible for this process.
"Stansted remains fully open and operational, but passengers should check with their airline for the latest flight information."
Ryanair told The Mirror: "Due to continued icy weather conditions, we are experiencing a small number of delays/cancellations to flights from some UK airports today (11 Dec), including London Stansted.
"While our teams are working hard to minimise disruption to customers, Ryanair advises all customers flying from the UK today (11 Dec) to check the Ryanair website/app for flight status updates before travelling to the airport.
"We sincerely apologise for these weather-related disruptions which are entirely beyond our control."
British Airways added: "We're very sorry as a result of adverse winter weather conditions, like other airlines, have had to reduce our schedule at Heathrow today.
"We're taking steps to ensure as many customers as possible are able to travel as planned.
"We've apologised to our customers and are offering to refund or rebook them onto alternative flights, providing refreshment vouchers and hotel accommodation where needed."
South Wales Police reported several crashes along the M4 corridor between Junction 35-39 Westbound, and urged drivers to take care in the cold weather conditions.
Warwickshire Police advised drivers to avoid travelling, particularly in the Stratford area.
A spokesperson for the force said: “Due to the high number of collisions in the south of Warwickshire this morning, one involving three cars at once, we are now asking motorists in the Stratford area to avoid travel unless it’s imperative.”
In the south east, Network Rail for Kent and Sussex reported severe disruption on some routes after some trains were delayed when the icy temperatures prevented them from getting electricity.
In Cambridgeshire, ice skaters frozen Fens today after the cold snap gave them the rare chance to enjoy the sport.
This is Britain’s worst cold spell since 2018’s Beast from the East.
Night temperatures are the coldest since a shorter cold period in February last year, which saw -23C (-9F), in Braemar, Aberdeenshire, the UK’s coldest temperature since 1995.
A Heathrow spokesperson said: "Poor weather conditions are forecast across the UK today and we want to reassure passengers that our colleagues are working in close collaboration with our airline and air traffic control partners to get them safely away on their journeys as quickly as possible.
"We encourage passengers to check their flight status with their airline for the latest information."
A Gatwick Airport spokesperson said: "Freezing weather conditions are causing some delays and cancellations today.
"Passengers are advised to check the status of their flight with the airline before they leave for the airport - and to allow extra time to travel to the airport."
