July in Iwakuni is the rainiest month of the year. In July, the weather in Iwakuni is typically hot. Average daily high temperature in July is about 28 degrees above zero. On average, Iwakuni has 19 rainy, 6 sunny, and 6 partly cloudy days in July. The rains are usually heavy. July as well as January, February, March, and June is considered the most uncomfortable time to visit Iwakuni.