Was it a white Christmas?

Using technology such as radar, webcams and ground based sensors combined with the expert opinion of experienced forecasters, the Met Office is able to declare whether or not (YES or NO) snow fell at the following locations on Christmas Day 2012:

London (Buckingham Palace)       NO 
Belfast (Aldergrove Airport)    NO
Liverpool (Albert Dock)        NO           
Brize Norton                    NO
Aberdeen (Pittodrie – Aberdeen FC)  NO           
Hurn                            NO
Glasgow Cathedral         NO           
Marham                          NO
Edinburgh (Castle)   NO           
Albemarle                       NO
Exeter Met Office         NO           
Filton                          NO
Manchester (Coronation Street) NO           
Andrewsfield                    NO
Leeds (Elland Road)   NO                
Waddington                   NO
Birmingham (Bullring)        NO           
Watnall                         NO
Cardiff (Millennium Stadium)        NO                   
Church Fenton                   NO

Top ten: Snowiest Christmas days

Snow at Christmas is recorded in two ways – the number of stations that reported snow falling, and the number of stations that recorded snow on the ground at 9 am. The two charts show the snowiest Christmases for both measures since 1959.

The snowiest Christmas in terms of snow on the ground was in 2010, when 83% of stations recorded snow.

	Year	Percentage of stations reporting snow lying
1	2010	83%
2	2009	57%
3	1981	52%
4	1995	40%
5	2004	34%
6	1999	30%
7	1964	22%
8	1993	21%
9	1970	20%
10	1968	14%

The year when the highest number of stations reported snow falling was 2004, when 61% of stations reported snowfall.

	Year	Percentage of stations reporting snowfall
1	2004	61%
2	1970	57%
3	1993	51%
4	1995	49%
5	1964	47%
6	1968	43%
7	1999	42%
8	2001	40%
9	2000	35%
10	1966	31%

Visit our website to see the full history of snow at Christmas or find out how much snow we get in the UK each year.

Related articles

• Will it snow this Christmas? (metofficenews.wordpress.com)

How do we measure snow?

Here at the Met Office, we’re already being asked if it’s going to be a White Christmas and there’s always a lot of interest in snow.

It’s too early to give forecasts that far ahead, forecasting snow is – after all – a challenge which requires detailed information. While forecasting snow is one challenge, measuring it when it’s on the ground poses another.

There are several reasons for this. First of all snow is subject to the vagaries of the wind and can be blown into deep drifts, leaving bald patches of earth nearby.

Snow also melts, refreezes, and new snow can fall on top. This makes it difficult to discern how much snow has fallen at different times or on different days.

Another tricky aspect of measuring snow is that it often falls on high ground, away from where the majority of the UK population live – and also away from our observation sites.

Snow often falls on high ground but is less common closer to sea-level.

So what do we do to measure this problematic precipitation? In days gone by a manual observer (ie a human being) would go out with a ruler and measure snow on a flat surface.

But this is time consuming, limits observations (as there were relatively few manual observers) and, apparently, became a tricky operation when snow got particularly deep!

So modern technology has given us automated snow sensors which measure snow depth with a laser signal. A piece of artificial turf is the preferred surface below the laser, as it doesn’t grow and therefore doesn’t complicate readings as grass might.

It’s not all that simple though, as even artificial turf can expand and contract according to temperature, as can the soil below it (which can push the artificial turf up or down). Moles can also cause the same problem! To tackle this, our network is under continual review and calibration to make it as accurate as possible.

These fairly technical pieces of kit can’t be placed everywhere, and until last year there were less than 50 spread out across the UK.

Snow depth sensor

This year we have extended our network with 21 new snow sensors, bringing the total up to 68 – you can see the full network on the map below.

Map showing snow sensor network in 2012

This means we can get snow readings from a wider range of locations, which can help our forecasting and is useful for building records and statistics about UK climate.

It’s worth pointing out that while these additions to our observation network are a valuable step forward, the snow sensor network is still relatively sparse in comparison to our UK land weather observation network, which has 463 stations.

Fortunately this is supplemented by observations supplied to the Weather Observations Website (WOW), where anyone can give an up to date measurement of snow or even upload a picture of how much snow they have.

The very nature of our weather here in the UK means that it’s not possible to give precise information for every location in the country, but our network is being continually improved to provide the most detailed, accurate and up-to-date information available.

You can read more about snow and snow forecasts on our dedicated snow pages.

Infographic: How often has it been a white Christmas

It may not look like it will snow at Christmas this year, but we’ve taken a look back at how often we’ve seen snow fall or snow on the ground on Christmas Day over the past 50 years.

For more information on snow at Christmas, take a look at our white Christmas page.

Met Office in the Media: 15 December 2010

Following widespread coverage around the likelihood of a White Christmas this year, The Independent, with the Met Office, takes a look at why it is still just too early to say for sure whether we will see the ‘White Stuff’ on Christmas Day. ‘Trillions of sums, but we can’t predict a white Christmas‘ focuses on the millions of calculations and the vast amount of information we use to forecast the weather 10 days ahead.

Many news outlets continue to focus on the return of cold weather across the UK with The Telegraph, Daily Mail, Guardian and the Daily Express.

The Met Office have also appeared on the BBC News Channel, BBC Scotland and across the BBC local radio stations, ensuring the public are aware of the impending severe weather.

Are you dreaming of a white Christmas?

It is that time of year again when many start to wonder whether we will see a white Christmas this year.

For many a white Christmas means a complete covering of snow, ideally falling on the 25th. However, the definition of an official white Christmas used most widely, notably by those placing and taking bets, is for a single snow flake (perhaps amongst a shower of rain and snow mixed) to be observed falling in the 24 hours of 25 December.

The last official white Christmas was in fact last year, when snow was widespread across Northern Ireland, Scotland, parts of Wales, the Midlands, north-east and far south-west England.

With the cold and snowy conditions already affecting many parts of the UK the question of a white Christmas is of course even more topical.  However it is just too early to say with any detail what the conditions will be in individual towns and cities across the UK.  Our 6 to  15 day forecast is available on our website and gives a general idea of the weather we can expect during the Christmas period, but we will really need to wait until the start of next week before we can provide more detail.