Shetland is an archipelago in Scotland, off the northeast coast. The islands lie to the northeast of Orkney, 280 km (170 mi) from the Faroe Islands and form part of the division between the Atlantic Ocean to the west and the North Sea to the east. The total area is approximately 1,466 km² (566 sq mi). Administratively, the area is one of the 32 council areas of Scotland. The islands' administrative centre and only burgh is Lerwick.
The largest island, known as "Mainland," has an area of 967 km² (374 sq mi), making it the third-largest Scottish island and the fifth-largest of the British Isles.
Shetland is also a lieutenancy area, comprises the Shetland constituency of the Scottish Parliament, and was formerly a county.
Out of the approximately 100 islands, only 15 are inhabited. The main island of the group is known as Mainland. The other inhabited islands are: Bressay, Burra, Fetlar, Muckle Roe, Papa Stour, Trondra, Vaila, Unst, Whalsay, Yell in the main Shetland group, plus Foula to the south-west, Fair Isle to the south, and Housay and Bruray in the Out Skerries to the east.
Fair Isle lies approximately halfway between Shetland and Orkney, but it is administered as part of Shetland. The Out Skerries lie east of the main group. Due to the islands' latitude, on clear winter nights the aurora borealis or "northern lights" can sometimes be seen in the sky, while in summer there is almost perpetual daylight, a state of affairs known locally as the "simmer dim".
Shetland has a Maritime Subarctic climate. The climate all year round is mild due to the influence of the relative warmth of the surrounding seas, the surface temperature of which falls to 5 °C (41 °F) in early March and peaks at 13 to 14°C (55-57°F) in late August. However, summers are cool and temperatures over 21 °C (70 °F) are rare. The warmest month on record was August 1947, when the average maximum temperature was 17.2 °C (63.0 °F).
The general character of the climate is windy and cloudy with at least 1 mm (0.039 in) of rain falling on about 200 days a year. Average yearly precipitation at Lerwick is 1,238 mm (48.7 in), with November and December the wettest months, together receiving about a quarter of annual precipitation. Snowfall can occur at any time from July to early June although it seldom lies on the ground for more than a day. Less rain falls from April to August although no month receives less than 50 mm (2.0 in). Fog is common in the east of the islands during summer due to the cooling effect of the sea on mild southerly airflows.
There is a wide variation in day length during the course of the year due the islands' northerly location. On the shortest day at the winter solstice sunlight lasts 3 hours and 45 minutes and this stretches to 23 hours at the summer solstice, with twilight occupying the remainder of the time. However, the remoteness of the islands from warm and dry airflows means that all months are cloudy. Annual sunshine hours average 1065 hours so sunny days are rare and overcast days are common.