July in Sendai is the rainiest month of the year. In July, the weather in Sendai is typically warm. Average daily high temperature in July is about 26 degrees above zero. On average, Sendai has 19 rainy, 5 partly cloudy, 4 cloudy, and 3 sunny days in July. The rains are usually heavy. July as well as January, February, March, and April is considered the most uncomfortable time to visit Sendai.