Sporting events across the UK have been cancelled because of snowfall and icy conditions - with forecasters predicting overnight temperatures were the coldest of the week so far.
Lows of -11C in Aberdeenshire and -8C in rural Wales were forecast for Saturday morning, with a series of yellow weather warnings for snow and ice in force until 10am or 11am this morning.
Alerts cover the far north of Scotland and Cumbria to southwestern Scotland, as well as southern and eastern coasts of England.
Crewe's match with Bristol Rovers in the second round of the FA Cup has been called off because of an unsafe playing surface - as well as several Scottish Professional Football League games.
And Saturday's high-profile racing fixture at Newcastle, which was due to stage the return of the Constitution Hill, has been abandoned due to snow on the track.
People are being warned about slips and falls on icy surfaces, while drivers may face treacherous conditions and public transport could be delayed.
Sky News weather presenter Kirsty McCabe said: "At the moment, outbreaks of rain, sleet and snow are set to move in from the west on Saturday night.
"This awkward mix will push eastwards across parts of England and Wales.
"Snow is most likely over the Welsh hills but could fall to lower levels overnight as the temperatures drop well below freezing.
"As well as a risk of snow, there is the potential for icy stretches and freezing rain (which causes black ice on roads).
"Other wintry hazards this weekend include freezing fog, which is likely to linger and make it feel even colder."
However, Sunday could bring a small increase in temperature in many parts of southern England.
Health and transport risks ahead
The UK Health Security Agency has issued amber cold health alerts in five regions - the East Midlands, West Midlands, North West, North East, and Yorkshire and the Humber - until 5 December.
It says there could be a "significant" impact across the health and social care sector.
According to the Met Office, the UK is likely to remain in a northeasterly airflow for several days to come, meaning it will stay cold well into next week.
National Highways is urging motorists to plan their journeys, keep an eye on the weather forecast, and take extra care on the roads.
Its national network manager Dale Hipkiss said: "Freezing conditions bring so many hazards such as snow and ice.
"Please take every possible step to understand your journey in advance and allow extra time when travelling.
"Keeping a kit of essential items like a torch and warm clothes in your vehicle can be vital."