Planning for the weather is a good way to make your trip to Hongcheon relaxing and enjoyable, especially when you’re splurging. The hottest months are usually August and July with an average temp of 70°F, while the coldest months are January and December with an average of 29°F. The rainiest months in Hongcheon are July, August, September, and June, with each month seeing an average of 9 inches of rainfall.