Freezing fog lingered over much of England on Saturday as the country emerged from its coldest night of the winter so far.
Overnight temperatures at Redesdale Camp in Northumberland plunged to minus 11.1C (12F), the Met Office said.
Northern Ireland also recorded its coldest night, with a temperature of minus 10.2C (14F) in Katesbridge, Co Down.
There were bright and sunny spells for much of central and southern England as well as Wales on Saturday afternoon, but much of Scotland saw cloudy and windy conditions, with some rain and hill snow.
Warnings for ice, snow and rain have been issued for Scotland over the weekend.
From 6pm, a yellow warning for ice covers much of mainland Scotland until 11am on Sunday.
From 6pm on Sunday a warning for rain covers north-western Scotland until 6pm on Monday, while a snow warning for the Orkney and Shetland isles is in place from 6am on Sunday until 9am on Monday.
People in areas with frost and ice were warned of injuries from slips and falls on hazardous surfaces, dangerous driving conditions and delays to public transport.
The freezing fog is expected to linger in southern parts through Sunday, but there will be sunny spells for many, with temperatures to stay cool at between 4C and 7C.
Ben Aldous, of the RAC, said: “Fog, ice and in some places snow are the enemies of drivers.
“In order to avoid falling foul of the conditions it’s important for motorists to adjust their driving style to suit the conditions.
“Being gentler on the throttle and brakes, and slowing down particularly on rural or ungritted routes can help ensure a safe and trouble-free journey.”
He also urged drivers to check their tyres have plenty of tread and are properly inflated and that windscreens are “completely cleared of ice and snow”.