October in Seosan is the sunniest month of the year. In October, the weather in Seosan is typically warm. Average daily high temperature in October is about 17 degrees above zero. On average, Seosan has 15 sunny, 9 partly cloudy, 6 rainy, and 1 cloudy day in October. The rains are usually heavy. October as well as September is considered the most comfortable time to visit Seosan.