Heavy snowfall has led to travel disruption as freezing weather grips the UK.
Police forces across the country have warned of treacherous conditions on the roads during the Tuesday morning rush hour after temperatures plummeted overnight.
Two yellow severe weather warnings for snow and ice are in force, with one covering Wales, northern England and Midlothian until 3pm as a spell of sleet and snow moves south-eastwards.
A further yellow snow and ice warning is in place until 10am on Wednesday as sleet, snow and hail showers, some heavy, hit western areas.
The Met Office has updated another warning of snow and ice in effect from 3pm on Tuesday until 9.30am on Wednesday for parts of eastern England.
The wintry conditions are expected to continue into the weekend and there are warnings that Britain could face unusually cold weather for the rest of the month.
Met Office forecaster Alex Burkill said: "There are indications of quite a prolonged cold period."
Snow is set to fall in almost every part of the country in the coming days, with this week predicted to be one of the coldest of the winter so far.
Between 1cm and 3cm of snow is expected to fall widely on Tuesday and hilly areas could see up to 5cm.
Mr Burkill said: "As we go through the next 24 to 48 hours, it's going to stay cold, and we are going to see some snow and pretty much anywhere in the country could see something."
British Airways said 70 short-haul flights to and from London's Heathrow Airport did not operate on Monday due to the weather and a further 10 have been cancelled on Tuesday.
Temperatures will dip further on Tuesday night - and could sink as low as minus 11C in parts of Scotland and northern England.
Another band of snow, sleet and rain will sweep across the country from Wednesday to Thursday and bring a "milder blip" in the weather, Mr Burkill said.
But he added: "The cold weather is likely to return as we go towards the weekend.
"Really much of February and perhaps even into March it is going to stay on the cold side, so temperatures generally below average, with further frosts and also the risk of rain, sleet and snow as well."