Weather warnings for snow and ice have been issued for large parts of the UK, with temperatures set to plummet to below freezing on Thursday.
The Met Office has issued two yellow severe weather alerts until 11am – warning that snow could arrive early on Thursday, with 2cm to 5cm possible over northern Scotland and northeast England.
There is also the risk of snow in the East Midlands and East Anglia.
Temperatures overnight are expected to plunge to -4C in central parts where skies will remain mostly clear.
Forecasters have put out an ice warning for Northern Ireland, southwest England and Wales.
Roads and railways are likely to be affected, with disruption to public transport.
Freezing temperatures and showers will cause wet surfaces to freeze, with the Thursday morning commute causing hazardous road surfaces.
Northeastern Scotland and the east coast of England will have rain, sleet and snow.
Drivers are being warned to take care due to potential poor visibility at times which could make driving conditions dangerous.
Even when the weather warnings are lifted, snow showers are still expected throughout the day.
The Met Office’s chief meteorologist, Steve Willington, said: “Across the UK people will be feeling some pretty raw conditions as we go towards the start of winter, Thursday will feel especially cold with a biting northerly wind.
“Many parts of central Britain will have a very bright week with lots of sunshine.
“However, both east and west coasts will see frequent showers, some of which could be wintry over the hills and maybe down to lower levels by the end of the week in the east.
“This is exactly the sort of weather we would expect to see as we head into the winter months. The weekend looks to be mostly dry although it will be greyer and feeling slightly milder.”
There are potential further warnings for Friday, but things are expected to calm down into the weekend.
Areas not affected by the warnings, especially away from the coast, will see “lots of bright, sunny weather” during the week, the Met Office added.
The cold weather is being brought in from the Arctic by an area of low pressure to the east and a ridge of high pressure to the west.
Older people are being told to take precautions in light of the weather warnings.
Caroline Abrahams, charity director at Age UK, said: “The cold weather is challenging for many older people, particularly if they are coping with ill health or living in housing that costs a lot to heat.”
She said the elderly find it harder to adjust to big changes in temperature, with heart attacks and strokes more likely due to the cold raising blood pressure.
Breathing in cold air can increase the risk of “serious illness like flu and pneumonia”, she warned.
Ms Abrahams added: “Simple precautions such as wrapping up warm when going outside, sleeping with the windows closed at night and having plenty of hot food and drinks throughout the day can help keep these risks at bay.
“We would also urge everyone to keep a friendly eye on older relatives, friends and neighbours, especially when the weather is very bad and it’s difficult to get out.
“Offering to bring in some shopping, or just popping in for a chat and a cup of tea, can be a real help during the long winter months.”