Saitama Prefecture Tokyo Metropolis Niiza has a humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall.

On March 1, 1955, Owada annexed the neighboring village of Katayama becoming Niiza Town, which was raised to city status on November 1, 1970.

[5] Niiza has a mayor-council form of government with a directly elected mayor and a unicameral city council of 26 members.

Toppan printing has a large factory in Niiza, which is also home to a number of other light manufacturing, electronics and transportation/warehousing companies.

However, due to its proximity to Tokyo, over a third of the workforce commutes daily, making Niiza largely a bedroom community.