Christmas Day temperatures fell below -17C in some areas, and forecasters warned there will be little respite from the cold until next year.
Edinburgh, Glasgow, Aberdeen and north-east England can all claim to have had a white Christmas - but forecasters said there was more snow on the ground than came through the air.
Most of the UK saw crisp wintry conditions with clear blue skies and freezing temperatures.
The lowest was recorded at Castlederg in Northern Ireland where the mercury plummeted to -17.1C at 9am.
London was grey and gloomy, but bookmakers' spirits were raised as the popular bet of Christmas snow in the capital failed to pay off. Coral's David Stevens said: "Fresh snowfall across the UK would have won punters a multimillion-pound Christmas present. However, with the exception of parts of Scotland and north-east England, snow is in short supply and it looks like being a happy Christmas for the bookies."
The freezing conditions suffered throughout the month mean it could be the coldest December since records began.
Brendan Jones, forecaster with Meteogroup, the weather division of the Press Association, said: "It's reaching up there with some of the coldest Decembers we've had on record. We'll have to wait and see whether or not it is the coldest."
Temperatures are expected to rise slightly as southerly winds bring air that is not quite as cold as that endured recently. A band of rain will start in western parts of the UK on Boxing Day before moving to the east by Monday evening.
The Met Office issued a severe weather warning for Northern Ireland on Sunday as rain and sleet is predicted to cause ice on roads as it falls on to cold ground. Mr Jones added that although we appear to be over the current spell of cold weather in the short term, it will remain chilly into the New Year.
He said: "Once we get past Monday there's no seriously cold weather. But at this stage there's nothing very mild coming in either so 5C or 6C is more likely what we'll see. As we head towards next weekend we've got hints that it'll get colder again."