The wartime interest in Greenland was a direct result of its vital strategic position—if you wanted to predict the weather in Europe, you had to have men in place on the vast, frozen island. The most celebrated example of Greenland's crucial contribution to Allied meteorological services is the correct weather forecast in June 1944 leading to the decision to launch the invasion of Normandy. In addition, both before and after D-Day a stream of weather reports from Greenland was essential for the Allied ability to carry out the bombing offensive against Germany.
The Germans were aware of the value of Greenland from a meteorological point of view, and they repeatedly attempted to establish semi-permanent weather stations along the sparsely populated east coast of the island. This resulted in an epic cat-and-mouse game, in which US Coast Guard personnel assisted by a celebrated sledge patrol manned by Scandinavian adventurers struggled to locate and eliminate German bases before they could make any difference. It's a story seldom told, but the fact remains that Greenland was the only part of the North American continent in which German troops maintained a presence throughout almost the entirety of the war.
