The Kuril Islands, stretching 715 miles (1150 km), lie between the northern Japanese islands of Hokkaido and the Russian Kamchatka Peninsula. They are comprised of 32 islands with 1,495 miles (2406 km) of total coastline. The archipelago covers 6,023 mi² (15,600 km²). Islands range from 2 mi² (5 km²) to 77 mi² (200 km²) in area.

The Greater Kuril Islands are divided into three groups: southern, central, and northern islands. Major straits run between the three groups, acting as physical and ecological barriers. The Bussol Strait, for example, is 67 miles (108 km) wide. In addition, the entire island chain is flanked by the Sea of Okhotsk to the west and the Pacific Ocean to the east. The waters off the coast are extremely deep. The Kuril-Kamchatka Trench, to the east, and the Kuril Basin, to the west, reach depths upwards of 27,885 ft (8500 m) and 11,155 ft (3400 m) respectively.

The Kuril Islands' climate is characterized by severe and unpredictable weather. During the winter, sea ice forms in Sea of Okhotsk covering one-third of the sea. The mean temperatures for entire island chain in February are around 21° and 22°F (-5.3° and -5.9°C).

Sea ice remains in the Sea of Okhotsk for an average of 77 days per year. The summer months are considerably warmer, with the mean temperatures in August ranging from 61° to 62°F (16.1 to 16.3°C). Nonetheless, the number of frost free days only range from 120 days per year in the northern islands to 180 days per year in the southern islands. This maritime climate also produces heavy fog, which blankets the island chain for more than 180 days per year.