The Svalbard archipelago extends roughly from 74 to 81 degrees northern latitude, and from 10 to 35 degrees eastern longitude, between the Barents Sea, the Polar Sea and the North Atlantic. Its superficy of 63,000 square kilometres is about one and a half times that of Switzerland.
Large parts of the islands consist of sharp and steep mountain peaks, up to 1717 meters high (Newtontoppen and Perriertoppen). The north and west coast are deeply indented by fjords, some of which are more than 100 km long. Svalbard is geologically very interesting, since all main periods are represented and fossils are easy to find.
Nearly 60% of the land is covered by glaciers, the largest ones are located in the north-east. Most glaciers reach the sea, where they form impressive ice walls which can reach 50 meters height. In summer, these ice fronts are calving, producing icebergs of various sizes. Svalbard also displays very flat valleys free of ice, covered with lichen, flowers, and strange polygonal stone arrangements created by the frost.
Despite its northern location, Svalbard has a relatively mild climate, thanks to warm atmospheric and sea currents. On the west coast, temperatures in July are usually inside the range 1-10° C, with an average of 5° C. In February-March, the mean temperature is usually between -8° C and -16° C. The amount of precipitation is very small (less than 400 mm a year), and Svalbard is sometimes qualified as an arctic desert. The weather may change a lot between one valley and the next. Strong wind and fog are not unusual, but it is also possible to have very sunny and mild weather.
In Longyearbyen, midnight sun lasts from 19th April to 23rd August, while the polar night lasts from 26th October to 16th February (see this Sun Diagram). In the intermediate periods, the length of day changes quickly, and due to the flat orbit of the sun, the periods of twilight are long. During the polar night, the moon never sets for a period of several days around full moon. Northern lights can also be observed during this period.