Niiza is located at the southernmost tip of Saitama Prefecture, and is essentially a suburb of the Tokyo conurbation. The entire city is located on the Musashino Plateau, with the Yanase River running through the western part of the city, and the Kurome River running through the eastern part of the city. +more Niiza includes the southest point of Saitama Prefecture, which faces Nishitōkyō of Tokyo.
Niiza has a humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall. The average annual temperature in Niiza is 14. +more9 °C. The average annual rainfall is 1449 mm with September as the wettest month. The temperatures are highest on average in August, at around 26. 7 °C, and lowest in January, at around 4. 1 °C.
Per Japanese census data, the population of Niiza has increased rapidly from the 1960s.
The area of modern Niiza has been settled since prehistoric times. The was part for Shinra County within Musashi Province in the Nara period. +more Shinra County (新羅郡) was originally written with the same kanji as the ancient Korean kingdom of Silla, and the area was settled by immigrants from Silla in 758 AD. The name was changed to Niikura County (新座郡) in the Heian period.
The town of Owada was created within Niikura District, Saitama with the establishment of the modern municipalities system on April 1, 1889. Niikura District was abolished in 1896, becoming part of Kitaasachi District. +more On March 1, 1955, Owada annexed the neighboring village of Katayama becoming Niiza Town, which was raised to city status on November 1, 1970.
Niiza has a mayor-council form of government with a directly elected mayor and a unicameral city council of 26 members. Niiza contributes two members to the Saitama Prefectural Assembly. +more In terms of national politics, the city is part of Saitama 4th district of the lower house of the Diet of Japan. In the 2021 Japanese general election, from Saitama 4th district, was elected.
Primary and secondary schools: *Niiza has 17 public elementary schools and six public middle schools operated by the city government, and three public high schools operated by the Saitama Prefectural Board of Education. In addition, there are two private combined junior/senior high schools.
In popular culture
On April 7, 2003, Niiza gave the anime character Astro Boy an honorary citizenship to mark the date given as his birthdate in the original manga. Later in 2004, the theme music from the TV series would eventually be used to signal the departure of a train at JR Niiza Station on the JR Musashino Line.