Will we have a white Christmas? Thanks to Charles Dickens writing about it and Bing Crosby singing about it, snowy scenes have become synonymous with Christmas, but in the UK at least the chances of waking up to a thick blanket of snow are very slim. The Met Office defines a white Christmas to be at least one snowflake observed falling in the 24 hours of Christmas Day, somewhere in the UK. On average, just over half of all Christmas Days in the UK turn out to be a “white Christmas”, but a single flake in Edinburgh probably isn’t what most of us have in mind. The Dickensian scene of widespread snow lying on the ground on Christmas Day has occurred only four times in the UK since 1960 – in 1981, 1995, 2009 and 2010. Christmas in 2010 was particularly unusual, with snow on the ground at 83% of weather stations; the highest ever recorded. White Christmases were more common during the 18th and 19th centuries, with North Atlantic regions still in the grip of the little ice age. And prior to 1752, when Britain adopted the Gregorian calendar and lopped 11 days off the year, the chances of a white Christmas were even higher. But in recent decades global heating has lengthened the odds of a white Christmas.