Will it be a White Christmas?
Will it be a white Christmas this year? What counts as a white Christmas and how often do we have one.
Looking at climate history, wintry weather is more likely between January and March than December. Snow or sleet falls on average five days in December, compared to 7.6 days in January, 6.8 days in February and six days in March.
White Christmases were more frequent in the 18th and 19th centuries, even more so before the change of calendar in 1752 which effectively brought Christmas day back by 12 days. Climate change has also brought higher average temperatures over land and sea and this generally reduces the chances of a white Christmas.
What is a white Christmas?
For many people, a White Christmas means a complete covering of snow falling between midnight and midday on 25 December.
However, the definition used most widely, notably by those placing and taking bets, is for a single snowflake (perhaps among a mixed shower of rain and snow) to be observed falling in the 24 hours of 25 December at a specified location.
When did we last have a white Christmas?
Christmas 2010 was the last white Christmas. It was extremely unusual, as not only was there snow on the ground at 83% of stations - the highest amount ever recorded - but snow or sleet also fell at 19% of stations.
We also had a white Christmas in 2009, 13% of stations recorded snow or sleet falling, and 57% reported snow on the ground.