The lowest temperatures of 2014 for England, Wales and Northern Ireland were recorded overnight.
Katesbridge, County Down, hit -8.8C (16.2F). Benson, Oxon, fell to -7.6C with -6.7C at Pembrey Sands, Dyfed.
Latest figures show the UK’s coldest temperature of the year so far was -9C in Cromdale, Moray, on Saturday.Meanwhile a Met Office cold weather alert for northern England and the Midlands has warned of health risks for vulnerable people.
BBC Weather said Scotland saw temperatures fall to -7.7C in Braemar, Aberdeenshire, overnight from Sunday to Monday.
Benson had also previously held the record for the lowest temperature of the year in England when it reached -6.8C on 6 December.
Wales’ lowest temperature of the year was recorded in Pembrey Sands, south Wales.
BBC Weather’s Peter Sloss said the cold temperatures mean it is already colder now than it was during “a good chunk of last winter”, from January to March.
Sunshine on Monday was expected to raise temperatures during the day, he added.
The record lows come as parts of the UK have already been hit by sub-zero temperatures and forecasters warned of further plunging temperatures over the next three days.
A sharp frost is expected in some areas of England and Wales on Monday night, with the UK experiencing similar temperatures to those seen on Sunday night, BBC Weather said.
The Met Office alert remains in place until 12:00 GMT on Wednesday – BBC News
