General Outline of Tohoku

The Tohoku region is an area that consists of Aomori Prefecture, Iwate Prefecture, Miyagi Prefecture, Akita Prefecture, Yamagata Prefecture, Fukushima Prefecture, and Niigata Prefecture. It occupies about 30 percent of the area of Honshu Island. According to the national census in October 2015, the population is about 11,290,000 people.

The Tohoku region is located in the northeastern part to the northernmost tip of the Honshu Island and is surrounded by the Sea of Japan, the Pacific Ocean, and the Tsugaru Strait on three sides. The Tohoku region is on the North American Plate, and since the Pacific Plate sinks from the east side at the Japan Deep, active volcanoes are dotted parallel with the Japan Deep in the central part and the Sea of Japan side in the region. The 1000-2000 m Ou Mountain Range runs north to south in the central part of Tohoku, dotted with many “hot springs,” which is the benefit of magma. In parallel to the Ou Mountain Range, the Kitakami Mountain Range and Abukuma Mountains are gently ranged on the east side, and the Dewa and Echigo Mountains are on the west side. Tohoku is an area with many mountains.Rivers, such as the Kitakami River and Abukuma River, twist and turn between these mountains in three lines ranging north to south, and form the basins and the plains.

Climate

rainfall aomorirainfall sendai

Annual maximum depth of snow cover

Summer in Tohoku is comparatively cool in general. In winter it snows in Tohoku focusing on the Sea of Japan side. The four seasons are very clear. Since the steep high mountains divide Tohoku into east and west, the climate greatly differs between the Pacific Ocean side and the Sea of Japan side. In summer, the temperature seldom goes up very high on the Pacific Ocean side because the cold “yamase” wind blows, and it is relatively cool. On the other hand, on the Sea of Japan side, it is hot mainly on the basin areas. When winter comes on the Pacific Ocean side, fine weather continues and there is little snow fall. On the Sea of Japan side, much snow falls, and especially in the mountainous areas snow falls to about 5 m, which results in a world’s distinguished heavy snowfall area. Since the Tohoku region extends north and south, there is a difference of 4°C in the average temperature between northern and southern Tohoku. Although it is relatively mild in the spring cherry blossom season and the autumn foliage season during the day, it may become considerably cold in the morning and the evening even on flat lands. Moreover, in mountainous areas it is lower by 10°C or so than on flat lands. Be sure to take precautions against the cold.