July in Chiayi is the rainiest and the hottest month of the year. In July, the weather in Chiayi is typically hot. Average daily high temperature in July is about 30 degrees above zero. On average, Chiayi has 28 rainy and 3 sunny days in July. The rains are usually heavy. July as well as May, June, August, and September is considered the most uncomfortable time to visit Chiayi.