Kōsa, Kumamoto

Kōsa (甲佐町) is a town located in Kamimashiki District, Kumamoto Prefecture, Japan.

As of February 2017, the town has an estimated population of 10,924 and a density of 190 persons per km2. The total area is 57.87 km2.

Climate
Kōsa has a humid subtropical climate (Köppen climate classification Cfa) with hot, humid summers and cool winters. There is significant precipitation throughout the year, especially during June and July. The average annual temperature in Kōsa is 16.3 C. The average annual rainfall is 2145.6 mm with June as the wettest month. The temperatures are highest on average in August, at around 27.1 C, and lowest in January, at around 5.4 C. The highest temperature ever recorded in Kōsa was 37.9 C on 14 August 2018; the coldest temperature ever recorded was -8.8 C on 25 January 2016.

Demographics
Per Japanese census data, the population of Kōsa in 2020 is 10,132 people. Kōsa has been conducting censuses since 1920.

Sports
Since its inception in 1983, the Kumamoto Kōsa 10-Miler road race has seen several top rated achievements being set during the event, which is run in December. The most recent new world record for the 10 miles was set in December 2022 by Bernard Koech.