August in Matsumoto is the warmest month of the year. In August, the weather in Matsumoto is typically warm. Average daily high temperature in August is about 25 degrees above zero. On average, Matsumoto has 24 rainy, 5 sunny, and 2 partly cloudy days in August. The rains are usually heavy. August as well as February, March, June, and July is considered the most uncomfortable time to visit Matsumoto.