Winters in the eastern parts of Scandinavia are heavily influenced by high pressure fronts that move in from Northern Russia. This means that winter temperatures are influenced more by Russian cold than by the Gulf Stream that moves along the Norway’s coast in the west. Stable winter weather is also guaranteed by the regions proximity to the Arctic (the Polar Circle runs through Northern Sweden).

The terrain in North Sweden with its undulating hills that rise from the flat coast to the mountainous interior also play an important part in the region’s weather.

Microclimates exist in pockets throughout the interior because the cold air flows down and then is trapped in valleys. Temperatures in -40°C range are common in some low areas. Local inhabitants know the locations of different microclimates and can help in the planning of testing. In one day or in a week it is possible to test equipment in a number of different microclimates without having to travel great distances. Too, as winter gives way to spring, there are still extremely cold areas which make it possible to continue winter testing past usual dates.