During the glacial maximum in Scandinavia, only the western parts of Jutland (a part of Denmark) were ice-free during the glaciation and a large part of what is today the North Sea was dry land connecting Jutland with Britain. It is also in Denmark that the only finds of Scandinavian ice-age animals older than 13,000 BC are found. In the period following the last interglacial period before the current one (Eemian interglacial era) the coast of Norway was also ice-free.

The Baltic Sea, with its unique brackish water, is a result of meltwater from the Weichsel glaciation combining with saltwater from the North Sea when the straits between Sweden and Denmark opened. Initially, when the ice began melting about 10,300 ybp, seawater filled the isostatically depressed area, a temporary marine incursion that geologists dub the Yoldia Sea. Then as post-glacial isostatic rebound lifted the region about 9500 ybp, the deepest basin of the Baltic became a freshwater lake, in palaeological contexts referred to as Ancylus Lake, which is identifiable in the freshwater fauna found in sediment cores. The lake was filled by glacial runoff, but as worldwide sea level continued rising, saltwater again breached the sill about 8000 ybp, forming a marine Littorina Sea which was followed by another freshwater phase before the present brackish marine system was established. "At its present state of development, the marine life of the Baltic Sea is less than about 4000 years old," Drs Thulin and Andrushaitis remarked when reviewing these sequences in 2003.

Overlaying ice had exerted pressure on the earth's surface. As a result of melting ice, the land has continued to rise yearly in Scandinavia, mostly in northern Sweden and Finland where the land is rising at a rate of as much as 8-9 mm per year, or 1 meters in 100 years. This is important for archeologists since a village that was coastal in the Nordic Stone Age now is inland.