The UK is bracing for the coldest night of the year tonight, with the mercury plunging to -15C in some isolated Scottish glens, according to the Met Office.
The forecaster has said that central Scotland could be hit by as much as 40cm of snow later this week as the Arctic cold snap continues.
The forecasting body said that while there is some uncertainty about precisely where snow will cover and how deep it could be, 30cm-40cm is expected across the Central Belt and Southern Highlands on Thursday and Friday.
Northern England could meanwhile see 15cm-20cm of snow cover even in lower-lying areas as the cold snap gets even chillier.
People in southern England and South Wales can expect to wake up to snow on Wednesday but it is unclear whether it will settle, the Met Office said.
Snow is more likely to settle when it moves across much of northern England, Northern Ireland and much of Scotland on Thursday.
Met Office spokesman Stephen Dixon said snow should fall where cold Arctic air moving south towards the UK meets warmer air moving up from the south west.
“As we move into the weekend as that low pressure has moved out from the east, there is a further band of rain likely to move from the south west, which could knock against cooler air and create sleet showers,” he said.
“Next week there will be a gradual warming back to something a little bit more typical for the time of year.”
A yellow weather warning for snow and ice is in place in much of northern and eastern Scotland and north-east England until 10am on Wednesday. London, the south of England and South Wales will be covered by a yellow warning for snow and ice all day on Wednesday and until 9am on Thursday. A few centimetres could fall in those areas.
Northern England, North Wales, most of Scotland and Northern Ireland will be covered by a yellow warning for snow between 3am on Thursday and 6pm on Friday.
More than 10cm of snow fell in parts of northern Scotland on Monday as the cold snap brought snow, ice, wind and rain.
Temperatures dipped to minus 7.6C at Altnaharra in the Scottish Highlands on Monday night and the small hamlet was covered in 12cm of snow, more than anywhere else in the UK.
Snow has also settled across Northumberland and North Yorkshire, with some spots experiencing 2cm-3cm of cover.
The Met Office has warned people of possible delays on roads, railways and buses and said people could injure themselves by slipping on ice.
Homes in some rural areas may be cut off from the grid while others may experience power cuts and phone signal could become patchy.
The RAC has said it is “essential” drivers go out with blankets, food and drink and a phone charger in case they get stuck.
“Anyone who isn’t confident with winter driving might want to postpone their journey until temperatures increase,” said breakdown spokesman Rod Dennis.
The UK Health Security Agency has issued a level-three cold weather alert for the whole of England, which is set to last until midnight on Thursday.
Dr Agostinho Sousa, the agency’s head of extreme events and health protection, said people should check on vulnerable relatives and advised pensioners and anyone with an underlying health condition to heat their home to at least 18C.
Additional reporting by agencies.
