 The average annual rainfall is 982 millimetres (38.7 in) in Orkney and 1,168 millimetres (46.0 in) in Shetland. Winds are a key feature of the climate and even in summer there are almost constant breezes. In winter, there are frequent strong winds, with an average of 52 hours of gales being recorded annually in Orkney. Burradale wind farm on Shetland, which operates with five Vestas V47 660 kW turbines, achieved a world record of 57.9 % capacity over the course of 2005 due to the persistent strong winds.
