Kōriyama has a Humid subtropical climate (Köppen Cfa) characterized by hot wet summers and cool, quite dry winters.

Nearby centers, such as Nihonmatsu developed into castle towns under Hatakeyama clan and which were later controlled by the Date clan, Kōriyama remained as a commercial center and thrived as a post town because of its importance as a traffic focal point into the Edo period and was part of the territory of Nihonmatsu Domain.

In the early Meiji period, many dispossessed samurai were assigned undeveloped lands in the area to reclaim and as a result, the population grew and region developed into an agricultural center.

Kōriyama was raised from town to city status on September 1, 1924 with the annexation of neighboring Odawara Village.

On March 11, 2011, the Great East Japan Earthquake caused damage, but Kōriyama is located outside of the mandatory evacuation zone set by the Japanese government after the Fukushima Daiichi nuclear disaster.

[7] Kōriyama has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 38 members.

[citation needed] Kōriyama is an important transportation hub, as it is located in the center of Fukushima Prefecture and is the nexus of several railway lines and expressways.

Both Engaged to the Unidentified (未確認で進行形 - Mikakunin de Shinkoukei) and Kimi to Pico-Pico (きみとピコピコ) manga take place in the city.