The coldest days of each year 1900 -19.4 Braemar 11 February
1901 -18.8 Swarraton (Hants.) 9 January
1902 -18.9 Lairg 14 February
1903 -17.2 Braemar 13 January
1904 -14.4 Appleby (Cumbria) 27 November
1905 -15.0 Braemar 18 November
1906 -16.8 Woodbridge (Suffolk) 30 December
1907 -15.0 Llangammarch Wells (Powys) 25 January
1908 -18.3 Liphook (Hants.) 30 December
1909 -17.8 Marlborough 3 March, Balmoral 7 December
1910 -23.3 Balmoral 28 January
1911 -12.2 Garforth 1 February
1912 -20.6 West Linton 4 February
1913 -15.6 Braemar 31 December
1914 -13.9 Braemar 25 December
1915 -13.3 Balmoral 5 December
1916 -16.7 Braemar 20 February
1917 -20.0 Benson (Oxon) 6 February
1918 -19.4 West Linton (Borders) 14 January
1919 -23.3 Braemar 14 November
1920 -18.3 Raunds 13 December
1921 -15.0 Braemar 7 March
1922 -13.3 West inton, Eskdalemuir, Garforth 18 January
1923 -14.4 Braemar 25 Decembe
1924 -16.7 Balmoral 3 March
1925 -16.7 Braemar 20 December
1926 -16.7 Luton 17 January
1927 -17.8 Braemar 18 December; Logie Coldstone 17, 18 December
1928 -13.3 Braemar 1 January
1929 -18.3 Usk (Gwent), Ross-on-Wye 14 February; Houghall (Durham)17 February
1930 -16.1 Newport (Gwent) 20 March
1931 -17.2 Braemar 3 March
1932 -11.7 Dalwhinnie 12 March
1933 -15.6 Logie Coldstone 19 January
1934 -12.2 Braemar 14 March
1935 -15.6 Braemar 24 December
1936 -15.0 Braemar 5, 13 February
1937 -21.7 Braemar 13 December
1938 -15.6 Braemar 22 December
1939 -17.2 Dalwhinnie, Braemar 4 January
1940 -23.3 Rhayader (powys) 21 January
1941 -21.1 Houghall (Durham) 5 January; West Linton (Borders) 6 January
1942 -19.4 Braemar 8 March
1943 -13.9 Braemar 5 January
1944 -15.0 Braemar 28 February
1945 -19.4 Dalwhinnie 26 January
1946 -14.4 Dalwhinnie 26 February
1947 -21.1 Elmstone (Kent) 29 January; Peebles, Braemar 4 March,; Braemar 8 March
1948 -15.6 Logie Coldstone 24 January
1949 -17.8 Braemar 5 January
1950 -18.3 Dalwhinnie 15 December
1951 -16.1 Dalwhinnie 11 March
1952 -17.2 Logie Coldstone 30 January
1953 -12.8 Braemar, Dalwhinnie 3 January
1954 -20.0 Welshpool 2 February
1955 -25.0 Braemar 23 February
1956 -18.9 Perth 3 February
1957 -16.1 Sutton Bonnington (Notts.) 20 February
1958 -22.8 Logie Coldstone (Grampian) 14 March
1959 -17.8 Braemar 15 January; Kincraig (Highland) 4 February
1960 -22.2 Grantown-on-Spey 18 February
1961 -22.2 Cannich (Highland) 30 December
1962 -21.1 Corwen (Clwyd) 2 January
1963 -22.2 Braemar 18 January
1964 -15.5 Caldecott (Leics.) 29 December
1965 -21.7 Corwen (Clwyd) 3 March
1966 -20.0 Braemar 15 Februar
1967 -14.4 Carnwath (Strathclyde) 10 December
1968 -18.3 Braemar 21 February
1969 -20.6 Grantown-on-Spey 18 February
1970 -21.1 Carnwath (Strathclyde), West Linton (Borders) 7 January
1971 -12.8 Braemar 4 January
1972 -18.5 Moorhouse (Cumbria) 31 January
1973 -21.2 Carnwath (Strathclyde) 15 February
1974 -10.2 Lagganlia (Highland) 14 February
1975 -11.4 Balmoral 8 February
1976 -16.2 Carnwath (Strathclyde) 5 December
1977 -18.7 Lagganlia (Highland) 17 January
1978 -22.0 Keith (Grampian) 20 February
1979 -24.6 Carnwath (Strathclyde) 13 January
1980 -17.5 Clashnoir (Grampian) 2 January
1981 -25.2 Shawbury (Shrops.) 13 December
1982 -27.2 Braemar 10 January
1983 -11.5 St. Harmon (Powys) 23 November
1984 -23.6 Grantown-on-Spey 20 January
1985 -23.4 Lagganlia (Highland) 27 January
1986 -21.2 Grantown-on-Spey 27 February
1987 -23.3 Caldecott (Leics.) 13 January
1988 -11.6 Carnwath (Strathclyde) 22 November
1989 -14.0 Tummell Bridge 15 December
1990 -8.4 Grantown-on-Spey 15 February
1991 -16.0 Cawood (N Yorks.) 14 February
1992 -12.3 Worcester 22, 23 January
1993 -15.8 Altnaharra 26 December
1994 -13.8 Strathallan (Perth.) 17 February
1995 -27.2 Altnaharra 30 December
1996 -13.0 Aviemore 25 December
1997 -15.2 Shepshed (Lincs.) 3 January
1998 -17.0 Altnaharra 1 March
1999 -14.0 Sennybridge (south Wales) 20 December
2000 -15.0 Dalmally (Argyll) 30 December
2001 -21.7 Kibrace (Caithneess) 3 March
2002 -16.1 Grantown 2 January
2003 -18.3 Aviemore 7 January
2004 -15.2 Kinbrace (Sutherland) 19 December
2005 -13.2 Ravensworth (North Yorks.) 29 December
2006 -16.4 Altnaharra 2 March
2007 -13.0 Aboyne 22 December
2008 -12.9 Aviemore 30 December
2009 -18.9 Aviemore 8 January
2010 - -22.3C. Altnaharra Friday, 8 January 2010
The lowest temperatures occur early in the morning of clear above a layer of fresh snow (which is an excellent insulator and allows the air above it to cool radiatively. An absence of winds prevents warming by mixing of layers of air. Valley bottoms can act as frost hollows, permitting low temperatures. In Scotland and Northern Irleand the lowest temperatures usually occur in Arctic air with northerly winds. In the south, the coldest winter days happen when very cold continental air is brought in from the east. In the south the easterly air mass has to cross a smaller area of warming water (the Channel) than east Scotland, say, where the North Sea is much wider. On the other hand, the nights are longer in Scotland, and snow cover is more frequent. Although continental air is cold in winer, the exact degree of coldness depends on its origin and the track followed by the air mass from its source. AIr that comes straight from northern Russia over Poland and Germany can be exceptionally cold (e.g. as happened most notably in 1987, and most recently 1991). If the easterly blows from the Balkans and east Mediterranean it is less much less cold (about 5C) and the weather tends to be damp and grey.
Low minima in summer happen on still nights with clear skies, over sandy soils, which are also poor conductors of heat.