Planning for the weather is a good way to make your trip to Gunsan relaxing and enjoyable, especially when you’re splurging. The hottest months are usually August and July, with an average temperature of 23°C, while the coldest months are January and February, with an average of 3°C. The rainiest months in Gunsan are July, August, September and June, with each month seeing an average of 230 mm of rainfall.