White Christmas for some areas of UK
It has officially been a white Christmas in the UK for some, with areas of Cumbria and the south of Scotland recording light snowfall.
The Met Office confirmed the snowfall in Spadeadam, Cumbria, at about 22:00 GMT.
In a tweet, the forecaster added that parts of the south of Scotland were "also seeing rain turn to snow".
More wintry showers are expected, with the chance of up to 10cm of snow on the highest ground in Scotland.
The last officially white Christmas was recorded in 2014, when parts of the Northern Isles in Scotland had some snowfall.
A white Christmas used to be defined as the sighting, by a professional meteorologist, of one snow flake falling on the roof of the London Weather Centre.
The Met Office has widened the rule to include other parts of the country.
However, the snow still must be seen by a professional to count.
The Met Office has warnings covering southern, central and eastern Scotland and the most northern parts of England.
Met forecaster Mark Wilson said the temperature would turn colder on Boxing Day, with averages of 2C and 4C in Scotland, and between 7C and 9C in the south of the UK.
It is also alerting people in Wales and central England to expect rain and snow from 18:00 GMT on Boxing Day until 11:00 GMT on Wednesday.
Persistent rain moving east, from Wales into England, is likely to turn to snow early on Wednesday.
Most of the UK enjoyed a mild Christmas Day, although it has been wet in some areas.
The highest temperature - of 12.5C - was recorded in Hawarden, Flintshire, in north-east Wales.
It failed to match the Christmas Day record of 15.6C in Killerton, Devon in 1920.