Svalbard is a Norwegian archipelago in the Arctic Ocean. The climate of Svalbard is principally a result of its latitude, which is between 74° and 81° north. Climate is defined by the World Meteorological Organization as the average weather over a 30-year period. The North Atlantic Current moderates Svalbard's temperatures, particularly during winter, giving it up to 20 °C (36 °F) higher winter temperature than similar latitudes in continental Russia and Canada. This keeps the surrounding waters open and navigable most of the year. The interior fjord areas and valleys, sheltered by the mountains, have fewer temperature differences than the coast, with about 2 °C lower summer temperatures and 3 °C higher winter temperatures. On the south of the largest island, Spitsbergen, the temperature is slightly higher than further north and west. During winter, the temperature difference between south and north is typically 5 °C, and about 3 °C in summer. Bear Island (Bjørnøya) has average temperatures even higher than the rest of the archipelago.