April in Yamagata is the windiest and the sunniest month of the year. In April, the weather in Yamagata is typically warm. Average daily high temperature in April is about 10 degrees above zero. On average, Yamagata has 19 rainy, 7 sunny, and 4 partly cloudy days in April. The rains are usually heavy. April as well as March, July, August, and October is considered the most uncomfortable time to visit Yamagata.