The first snow warning of the season has been issued for parts of the UK, with Scotland already experiencing early snowfalls.
The Met Office has put out a yellow alert for snow overnight in Yorkshire and Humber, North East England, East Midlands and south-west Scotland, Highlands and Eilean Siar, Central, Tayside and Fife and Grampian.
Aberdeen was among the first places to see significant early winter snow.
Up to two centimetres of snow may settle over parts of northern Scotland, the North Yorkshire Moors and over high ground of eastern England as far south as the Lincolnshire Wolds.
Ice will also be a risk as the temperature falls with frost for many, particularly in the West said Sky News weather presenter Nazaneen Ghaffar.
She added that the first plunge of Arctic air had been triggered by winds from a northerly direction.
"An area of high pressure is centred over southern Iceland allowing scattered showers to drift into eastern coastal fringes of England as well. As they hit the cold air they will turn increasingly wintry, with a mix of hail, sleet and snow," she said.
Hundreds of gritters are on standby to treat roads with twice as much salt available to use compared to last winter.
Peter Box, chairman of the Local Government Association's economy and transport board, said: "Whatever this winter throws at us, motorists and residents can count on council highways teams being well prepared to keep roads safe and traffic moving.
"They've got brand new gritters which use salt more effectively, the latest technology in snow ploughs and special quad-bikes and 4x4s to grit narrow or hilly roads."
Meanwhile, thousands of migrating birds have been dying before reaching England this week because of an appalling combination of fog and winds around the coast, according to the Royal Society for the Protection of Birds.
Some fishermen have told the charity of the deaths of many exhausted and disorientated "garden" birds plunging into the sea around their vessels, a spokesman said.
Late on Saturday night there should be milder air coming in from the north west making it warmer on Sunday although there will be cloud and rain.