A break in the clouds over summit of Snowdon, Snowdonia, North Wales. Snowdon (Welsh: Yr Wyddfa, pronounced [əɾ ˈwɪðva]) is the highest mountain in Wales and is Great Britain's highest mountain south of the Scottish Highlands. It has been described as "probably the busiest mountain in Britain." It is located in Snowdonia National Park (Parc Cenedlaethol Eryri) in Gwynedd. The summit is known as Yr Wyddfa ("the tumulus") and lies at an altitude of 1,085 metres (3,560 ft) above sea level. As the highest peak in Wales, Snowdon is one of three mountains climbed as part of the National Three Peaks Challenge.
The English name "Snowdon" comes from the Old English Snow Dun, meaning "snow hill" as Snowdon can offer significant falls of snow each winter from October to April, but in the past, rare fresh late-seasonal snow has been reported to fall on Snowdon, well into the months of May and June. Although the amount of snow on Snowdon in winter has varied significantly recently, 55% less snow had fallen in 2004 than in 1994.
Snowdon has one of the wettest climates in Great Britain, receiving an annual average of more than 4,500 millimetres (180 in) of precipitation. The annual average temperature is estimated to be around +2.5 degrees Celsius.