July in Kumamoto is the rainiest month of the year. In July, the weather in Kumamoto is typically hot. Average daily high temperature in July is about 29 degrees above zero. On average, Kumamoto has 18 rainy, 7 sunny, 4 partly cloudy, and 2 cloudy days in July. The rains are usually heavy. July as well as January, February, March, and June is considered the most uncomfortable time to visit Kumamoto.