answers: 2009
context: cancelled due to heavy snow on the ground. Winter of 2009–10 in Great Britain and Ireland The winter of 2009–10 in the United Kingdom (also called The Big Freeze of 2010 by British media) was a meteorological event that started on 16 December 2009, as part of the severe winter weather in Europe. January 2010 was provisionally the coldest January since 1987 across the country. A persistent pattern of cold northerly and easterly winds brought cold, moist air to the United Kingdom with many snow showers, fronts and polar lows bringing snowy weather with it. The first snowfall began on </s> 1988–2005 numbers from stations with at least 25 years of data. In the United Kingdom, white Christmases were more common from the 1550s to the 1850s, during the Little Ice Age; the last frost fair on the River Thames, however, was in the winter of 1813–14. The shift from the Julian to the Gregorian calendar in 1752 also slightly reduced the chance of a white Christmas, effectively moving Christmas earlier in the winter. An "official" white Christmas is defined by the Met Office as "one snowflake to be observed falling in the 24 hours of 25 December somewhere in the </s> UK", but formerly the snow had to be observed at the Met Office building in London. By the newer measure, over half of all years have white Christmases, with snow being observed 38 times in the 54 years A more "traditional" idea of snow-covered ground is less common, however, with only 4 occasions in the 51 years reporting snow on the ground at 9am at more than 40% of weather stations. Although most places in the UK do tend to see some snow in the winter, it generally falls in January and February. However white Christmases do occur, on average
question: when was the last time the uk had a white christmas