July in Gunsan is the rainiest month of the year. In July, the weather in Gunsan is typically warm. Average daily high temperature in July is about 25 degrees above zero. On average, Gunsan has 15 rainy, 7 sunny, 7 partly cloudy, and 2 cloudy days in July. The rains are usually heavy. July as well as January, February, March, and August is considered the most uncomfortable time to visit Gunsan.