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 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.
Svalbard is located in between two ocean currents – the warm Atlantic West Spitsbergen Current and the cold Arctic East Spitsbergen Current. These currents have a large impact on the climate of Svalbard and in the distribution of sea ice. The warm Atlantic current on the west coast leads to an average sea temperature of 5–7 °C. This causes a difference in sea ice distribution on Svalbard, with the east coast having a significantly larger area of ice-covered sea than the west coast.
Historical data
Due to its history of human occupation, Svalbard has one of the longest high-latitude meteorological records on earth. Computer models of global climate have long predicted enhanced greenhouse warming at such latitudes, so the Svalbard record is of particular interest. It shows approximately increase in 100 years; with increase in the last 30 years.
Meteorological data for Svalbard dates back to 1911. 60% of the archipelago is covered by glaciers, so by drilling for ice cores the climate before this time can be studied. Ice cores on Svalbard can reveal the climate going back 1,000 years, to the end of the Viking era. The Norwegian Polar Institute's research found that 1,000 years ago the climate on Svalbard was mild, allowing the seas to be navigable. This warmer climate lasted until the 1200s. After this time the climate was in a cold period, or a mini ice age, apart from around the 1750s when the climate was warmer. Data from ice cores has found the 20th century was the warmest century in the last 600 years.
Meteorology
Average summer temperatures on Svalbard range from in July, and winter temperatures from in January. The highest temperature ever recorded was in July 2020 and the coldest was in March 1986. The archipelago is the meeting place for cold polar air from the north and mild, wet sea air from the south. This creates low pressure and changeable weather with high wind speeds, particularly in winter; in January, a strong breeze is registered 17% of the time at Isfjord Radio, but only 1% of the time in July. In summer, particularly away from land, fog is common, with visibility under registered 20% of the time in July and 1% of the time in January, at Hopen and Bear Island. Precipitation is frequent, but falls in small quantities, typically less than in Western Spitsbergen. More rain falls in the uninhabited east side, where there can be more than .
Traditionally weather had been forecast for Spitsbergen, which because of the needs of expeditions and the governor's activities gave the most extreme weather on the archipelago. This included forecasts for weather-exposed locations such as Hinlopen, Sørkapp and Danes Island. As most people live in the sheltered area of Nordenskiöld Land, the forecast was often regarded as irrelevant. The Norwegian Meteorological Institute started from 14 October 2011 issuing two forecasts, one which is publicly broadcast and covers the main settlements of Longyearbyen, Barentsburg and Svea ("Nordenskiöld Land"), and one that covers the entire archipelago ("Spitsbergen").
Temperature averages for selected settlements
Climate change
The Arctic region is particularly vulnerable to climate change because the surface air temperatures are increasing at twice the global rate. The special climate of Svalbard – which includes the winter with perpetual darkness (October–February) and summer with perpetual light (April–August) – has a clear effect on the ecology, with many of the endemic species specially adapted to survive the harsh environment.