Geography of Scotland - Climate

Climate

The climate of Scotland is temperate and very changeable, but rarely extreme. Scotland is warmed by the North Atlantic Drift and given the northerly location of the country, experiences much milder conditions than areas on similar latitudes, such as Labrador in Canada—where icebergs are a common feature in winter.

Average temperatures are lower than in the rest of Great Britain, with the coldest ever UK temperature of −27.2 °C (−17.0 °F) recorded at Braemar in the Grampian Mountains, on January 10, 1982 and also at Altnaharra, Highland, on December 30, 1995. Winter maximums average 5.0 to 5.7 °C (41 to 42.3 °F), with summer maximums averaging 14.9 to 16.9 °C (58.8 to 62.4 °F). Western coastal areas of Scotland are warmer than the east and inland areas, due to the influence of the Atlantic currents, and the colder surface temperatures of the North Sea. The highest temperature recorded was 32.9 °C (91.2 °F) at Greycrook in the Scottish Borders on August 9, 2003.

Rainfall totals vary widely across Scotland—the western highlands of Scotland are one of the wettest places in the UK with annual rainfall up to 4,577 mm (180.2 in). Due to the mountainous topography of the western Highlands, this type of precipitation is orographic in nature, with the warm, wet air forced to rise on contact with the mountainous coast, where it consequently, cools and condenses, forming clouds. In comparison, much of eastern Scotland receives less than 870 mm (34.3 in) annually; lying in the rain shadow of the western uplands. Snowfall is less common in the lowlands, but becomes more common with altitude. Parts of the Highlands have an average of 36 to 105 snow days per year, while some western coastal areas have between 0 and 6 days with snow a year.

The Hebridean island of Tiree received a total of 329 hours of sunshine in May 1946 and again in May 1975, the highest number of sunshine hours ever recorded in one month in Scotland. On the longest day of the year there is no complete darkness over the northern isles of Scotland. Lerwick, in Shetland, has four hours more daylight at midsummer than London, although this is reversed in midwinter. Annual average sunshine totals vary from as little as 711–1140 hours in the Highlands and the north-west up to 1471–1540 hours on the extreme eastern and south-western coasts.

In common with the rest of the British Isles, wind prevails from the south-west, bringing warm, wet and unstable air from the Atlantic. The windiest areas of Scotland are in the north and west, with parts of the Outer Hebrides, Orkney and Shetland experiencing over 30 days with gales per year. Vigorous Atlantic depressions, also known as European windstorms, are a common feature of the autumn and winter in Scotland.