It's almost Christmas Day, and there's always talk of whether snow will fall or not, but what defines a true White Christmas?

In the UK, the definition of a White Christmas was set by the Met Office. It used to be that a snowflake had to fall on the Met Office's building in London, but today it's if just one snowflake falls somewhere.

In Ireland, Met Éireann similarly state that a White Christmas is defined by the measure of any quantity of snow falling anytime over Christmas Day. The last Irish white Christmas was in 2010, with a spectacular 27 cm of snow.

This year, the outlook is not positive, at least not if you were hoping for snow. Instead, skies clear for a sunny, if chilly, Christmas.

Some small light showers in Scotland could turn snowy, but in terms of a real, widespread White Christmas, there's no good news.