July in Yamaguchi is the rainiest month of the year. In July, the weather in Yamaguchi is typically warm. Average daily high temperature in July is about 27 degrees above zero. On average, Yamaguchi has 24 rainy, 5 sunny, and 2 partly 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 Yamaguchi.