Svalbard's climate is a combination of an Arctic climate (Köppen: ET) tempered by the North Atlantic Current. Nordenskiöld Land is the warmest and wettest part of the archipelago, caused by the convergence of mild and humid air from the south and cold air from the north. Average summer highs are typically while average winter highs are . Svalbard experiences midnight sun from 19 April through 23 August, polar night from 27 October through 14 February and civil polar night from 14 November through 29 January. However, due to shading from mountains, the sun is not visible in Svalbard until around 8 March. Snow typically covers the town from November through March. The warmest temperature ever record in Svalbard was an extraordinary in July 1977 and the coldest was a frigid in March 1986.