14 Dec 2012

What is the chance of a white Christmas?

As Christmas draws ever closer, I’ve had a lot of people asking me whether or not it is going to be a white Christmas this year. There’s no doubt that for most of us, the prospect of having a blanket of snow during the festive period is exciting – unless you’re travelling of course.

Before I take a look ahead at the latest trends for the festive period this year, I thought I’d take a look back at how often we’ve experienced a white Christmas in the past.

First of all, let me clear up the definition of a white Christmas. Most people tend to think that snow lying on the ground on Christmas day would count.

However, for the purpose of those placing and taking bets, it is defined as a single flake of snow (including mixed with rain) to be observed falling in the 24 hours of 25 December. This observation also has to be made officially by a trained weather observer.

White Christmases in the past

Looking back at capital cities in the UK during the last 52 years (since 1960), a white Christmas has occurred on the following number of occasions;

Cardiff – 4 (in 1990, 1993, 2001 and 2004)

London – 6 (in 1964, 1968, 1970, 1976, 1996, 1999)

Belfast – 11 (in 1962, 1964, 1966, 1980, 1993, 1995, 1996, 1998, 1999, 2001 and 2004)

Edinburgh – 11 (in 1926, 1963, 1968, 1980, 1986, 1993, 1995, 1998, 1999, 2000 and 2010)

The last white Christmas was in 2010, when snow fell at 19 per cent of weather stations. Even more remarkable, was that 83 per cent of weather stations had snow lying on the ground – the highest ever recorded.

December 2010 was a cold and snowy for much of the UK, with some parts of Scotland and northeast England having more than 50cm of snow lying on the ground at the beginning of the month.

Nowhere experienced a white Christmas in 2011, as it was very mild everywhere, with temperatures as high as 15C in eastern Scotland.

Where, statistically, is most likely to have a white Christmas?

The graphic below, from the Met Office, shows the average number of days of with falling snow in December.

As would be expected, it shows that snow is more likely to fall the further north and the higher up you go. This ties in well with Belfast and Edinburgh being the capital cities with the greatest number of white Christmases since 1960.

Another fact that you may be surprised to hear, is that snow is actually more common at Easter than Christmas in the UK.

What are the chances this year?

The first point to highlight is that Christmas day is still two weeks away, so a lot can change between now and then.

However, at the moment, it looks like there’ll be a reservoir of cold air lingering across central and eastern parts of Europe, with sub-zero temperatures and snow.

But for the festive period, the jet stream lies over or just to the south of the UK, which puts us in the path of low pressure systems.

This would bring unsettled weather, with strong winds, mild air and average or above temperatures. As a result, rain is most likely, with snow probably confined to the hills and mountains in the north.

At the moment, the only way that I can see the chance of snow being increased, is if an area of low pressure tracks so far south that it drags in cold air across Europe on its northern edge.

Don’t forget, you can get the latest forecast on the Channel 4 Weather website and I’ll keep you updated on the prospects of Christmas day snow on Twitter – @liamdutton

Data source: Met Office

Tweets by @liamdutton