Commuters have been warned to expect disruption to roads and public transport as a snowy blast dubbed “the Beast from the East” hits Britain.
Some parts of the UK are set to feel colder than the Arctic Circle as freezing temperatures continue into the week ahead.
Amber warnings of snow have been issued by the Met Office for north east, central and south eastern England on Tuesday, and eastern Scotland on Wednesday.
It warned of “heavy snow showers”, with a spokesman adding: “Travel delays on roads are likely, stranding some vehicles and passengers.
“Some delays and cancellations to rail and air travel are likely.
“There is a good chance that some rural communities could become cut off.
“Power cuts are likely and other services, such as mobile phones, may be affected.”
Widespread snow is forecast, and the Met Office has issued yellow weather warnings for Monday, Tuesday and Wednesday.
By the middle of the week, the majority of Britain is being warned of the potential for delays on the roads, trains and in the air.
A less severe yellow warning for snow is in place from Monday to Wednesday.
Greater Anglia (GA) said it was limiting its services from Monday in anticipation of the snowy blast.
An advisory on its website warned that due to the forecast of sub-zero temperatures next week and large amounts of snow, the rail operator planned to halt its Monday night train services at 10pm.
A limited service will run on Tuesday.
South Eastern urged passengers to finish their journeys before 6pm on Monday to avoid potential disruption.
Transport for London (TfL) warned passengers to check ahead of their journeys as disruptions were possible on Underground and Overground services due to the low temperatures forecast.
Train operator C2C also warned of limited services, advising trips after 9pm on Monday could be altered or cancelled.
Lows of minus 5C (23F) recorded over the weekend marked the lowest temperature in the week leading up to March 1, the first day of spring, since 1986.
The wind chill, which could see parts of the UK feeling as cold as minus 15C (5F), rivals the temperatures forecast for parts of northern Norway and Iceland.
The Met Office said that by the end of Wednesday, more than 20cm of snow may have accumulated in some parts of eastern England, Scotland and Northern Ireland.
Met Office meteorologist Charlie Powell said: “The UK is on track for some really cold weather this week. It’s not going to be record-breaking, but it’ll be pretty exceptional – winds are going to make it feel minus 10C (14F) to minus 15C (5F) during the day.
“We will see the first signs of that tonight in the shape of snow showers working all the way down the east coast.
“That continues into Monday, with snow showers moving across the country during the day before reaching Wales.
“Winds are then going to strengthen and we could see some easterly gales through the eastern Channel and east Anglia by the middle of the week.
“That’s going to make it feel really cold, daytime temperatures on Wednesday and Thursday will be struggling to get above freezing for most of the country.”
He added: “By Thursday evening, there are growing signs there could be some significant snowfall across southern England.
“Unusually for Britain, the snow is going to be quite dry, so it will blow around and gather in drifts and we could see some blizzard conditions.
“We don’t want to scare people, but people should make sure they are prepared for some seriously cold weather.”