Yunlin is located in the south-central part of western Taiwan at the northern end of the Jianan Plain. Nantou County lies to the east and the Taiwan Strait to the west, the Beigang River and Chiayi County define the southern border, with the Zhuoshui River and Changhua County to the north. Plains account for nine-tenths of the county area, while mountainous areas make up the remaining 10 percent. The county has a subtropical climate and a year-round average temperature of 22.6 degrees centigrade. Administratively, it is divided into 20 townships and cities, all in flatland areas except for the three mountainous areas of Douliu City, Gukeng Township, and Linnei Township.