July in Yamagata is the rainiest month of the year. In July, the weather in Yamagata is typically warm. Average daily high temperature in July is about 24 degrees above zero. On average, Yamagata has 26 rainy, 3 sunny, and 2 cloudy days in July. The rains are usually heavy. July as well as March, April, August, and October is considered the most uncomfortable time to visit Yamagata.