The Alaska Peninsula has intensely glaciated mountains indented with fjords that are bordered by cliffs. Several large lakes are on the peninsula. Treeless slopes along the Pacific coast of the Alaska Peninsula, Aniakchak National Monument. The climate is characterized by fog and rain, with the amount of precipitation varying little from month to month. In general, smaller islands receive less precipitation than larger islands.
Winds are often severe on the islands.
Pacific Ocean water moving northward through the straits between the islands produces complex mixing with Bering Sea water, including upwelling. The Pribilof Islands in the Bering Sea are about at the southern limit of the arctic ice pack in winter. At lower elevations, there is a luxuriant growth of tall grasses, flowering plants, and ferns, with thickets of low willows in some places. A little higher up, several types of heath cover vast areas. The boreal forest and coastal rainforest are slowly encroaching from the east on the area of this province.