The coldest recorded temperature in the UK is -27.2° C. It was recorded three times in Scotland, twice in Braemar, 11 February 1895 and 10 January 1982 and once in Altnaharra on 30 December 1995.
(The coldest recorded temperature in England so far, was -26.1° C, 10 January 1982 in Shawbury Shropshire. Brrrr!)