The deepest cover yesterday was 10.5in at Lough Fea in Londonderry, and the lowest temperature overnight had been minus 4.3C (24F) in Edinburgh.
The main risk is now from freezing conditions, said Frank Saunders, chief forecaster for the Met Office.
"Although some further slight snowfalls are likely, the focus switches to ice, with temperatures staying below zero over snow cover for many areas," he said.
The ice will make travelling to work difficult for many people tomorrow. In Wales, where 8in of snow had fallen, the roads were described yesterday as like ice rinks.
A man and a woman were rescued after spending 24 hours in a snowbound delivery van on a mountain road in Pembrokeshire. Engineers worked through Friday night to restore power to 10,000 homes across Wales.
Mango the Cocker Spaniel in Victoria Park, Bristol (PA)
However, last night in Newry and Downpatrick in Northern Ireland, 400 homes were still without electricity, as temperatures headed for minus 4C (25F).
The cause of all the misery is a disturbance that happened in early January, above the surface of the earth.
The disturbance hit the fast-moving winds above the Arctic, making them suddenly reverse, so that the air at the centre of the circle collapsed, warming as it moved.
The pressure from this then hit the jet stream that sits to the north of Britain and which normally shields the UK from polar weather, shifting the jet stream south.
This was what allowed in wetter and cooler conditions. Much colder air was dragged in, from places in the east such as Siberia.
Today, a yellow weather warning is in place for England, Wales, Northern Ireland and southern parts of Scotland, suggesting a risk of snow and ice.
The forecast suggests that by Tuesday, the warning will apply to most of Scotland but nowhere else, and that it will be lifted completely the next day.
However, meteorologists say the effects of sudden stratospheric warming are highly unpredictable and can last for up to six weeks.