The Higashimatsuyama Plateau extends to the central and northern parts of the town/ Saitama Prefecture Ranzan has a humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall.

The villages of Sugaya and Nanasato were created within Hiki District, Saitama with the establishment of the modern municipalities system on April 1, 1889.

Ranzan has a mayor-council form of government with a directly elected mayor and a unicameral town council of 13 members.

Ranzan, together with the towns of Tokigawa, Ogawa and Namekawa, contributes one member to the Saitama Prefectural Assembly.

In terms of national politics, the town is part of Saitama 10th district of the lower house of the Diet of Japan.