Snow is set to reach as far as the south coast overnight, while parts of Scotland could be blanketed in up to 30cm.
Amber snow warnings have now been issued for northern Scotland, with heavy snow due overnight and the possibility of temporary blizzard conditions.
Across the rest of the UK, a network of yellow warnings are in place for snow and ice.
While not everyone will see snow, it’s likely 1-3cm will fall in places – with the potential of 5-8cm in some locations and widespread ice.
As of Saturday lunchtime, more than 20cm (7.9in) of snow had fallen in northern Scotland, with 37cm (14.5in) in the village of Tomintoul in the Cairngorms.
On Sunday, the Met Office issued a fresh yellow warning for ice along parts of England’s North East and East coast.
Existing yellow warning areas have also been extended in Wales and South West England, while Scotland and Northern Ireland are also covered by snow and ice warnings.
Most of the yellow warning areas from Sunday persist into Monday, expiring between 11am and 12 noon.
The exception is a snow and ice warning for the North East and East coast of England, which is in force until the end of Monday.
The Met Office has warned of further scattered sleet and snow showers and icy patches on Monday and overnight into Tuesday morning for South West England and western parts of Wales.
That yellow warning expires at 11am.
The weather is expected to have an impact on transport, with those heading out urged to prepare for longer journey times by road.
Some delays and cancellations to rail and air travel are likely, as are power cuts, according to the Met Office.
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The Met Office said: “Winds should ease somewhat into Sunday, with showers by then most prevalent around coasts. Snow showers should finally begin to ease during Monday morning.
“With temperatures inland likely remaining below freezing through the weekend, thaw of lying snow is not expected.”
Meanwhile, the UK Health Security Agency (UKHSA) has issued amber warnings which will remain in place until 10am on 9 January.
The alert has been issued for the East Midlands, West Midlands, North East, North West, South East, South West, East of England, Yorkshire and the Humber, and London.
The UKHSA said it means the weather is “likely” to cause significant impacts across health and social care services, including a “rise in deaths” among those with health conditions or aged 65 or over.
