[citation needed] Mogami has a humid continental climate (Köppen climate classification Cfa) with large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold) winters.

During the Sengoku period, the area was under the control of the Mogami clan who built Oguni Castle.

After the start of the Meiji period, the area became part of Mogami District, Yamagata Prefecture.

The villages of Higashi-Oguni and Nishi-Oguni were established on April 1, 1889 with the creation of the modern municipalities system.

Modern Mogami is dependent on agriculture, forestry and seasonal tourism to its many hot spring resorts.