Question: when did the uk have a white christmas

title: White Christmas (weather)
text: 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 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 to 2015 . A more `` traditional '' idea of snow - covered ground is less common , however , with only 4 occasions in the 51 years to 2015 reporting snow on the ground at 9am at more than 40 % of weather stations . 

Answer: answer: In the United Kingdom , white Christmases were more common from the 1550s to the 1850s , during the Little Ice Age.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 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 to 2015 .