July in Okayama is the rainiest month of the year. In July, the weather in Okayama is typically hot. Average daily high temperature in July is about 29 degrees above zero. On average, Okayama has 15 rainy, 6 sunny, 6 cloudy, and 4 partly cloudy days in July. The rains are usually heavy. July as well as January, February, March, and December is considered the most uncomfortable time to visit Okayama.