The February 2009 Great Britain and Ireland snowfall was a prolonged period of snowfall that began on 1 February 2009. Some areas experienced their largest snowfall levels in 18 years. Snow fell over much of Western Europe. The United Kingdom's Met Office and Ireland's Met Éireann issued severe weather warnings in anticipation of the snowfall. More than 30 centimetres (12 in) of snow fell on parts of the North Downs and over 20 cm (8 in) in parts of the London area. Such snow accumulation is uncommon in London. On the morning of 6 February the majority of Great Britain and Ireland had snow cover, with the area surrounding the Bristol Channel being most affected – 55 cm (22 in) had settled overnight around Okehampton, Devon, South West England with similar depths in South Wales. In Ireland the highest totals were recorded around East Kildare and County Wicklow where up to 28 cm (11 in) fell around Naas, County Kildare and even more along the Wicklow Mountains. The last time such widespread snowfall affected Britain was in February 1991. On the 2nd a total of 32 cm (13 in) had fallen in Leatherhead, Surrey just south of the M25. Also 30 cm (12 in) had fallen over the South Downs and 26 cm (10 in) in higher areas of Brighton.

The winter of 1990–91 was a particularly cold winter in Western Europe, noted especially for its effect on the United Kingdom, and for two significantly heavy falls of snow which occurred in December 1990 and February 1991. Sandwiched in between was a period of high winds and heavy rain which caused widespread damage. The winter was the coldest since January 1987, and the snowfall experienced in many parts of the United Kingdom would not be seen again until the snowfall of February 2009.