Weather will likely play an important role when you plan your trip to Jumunjin-eup, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually August and July with an average temp of 70°F, while the coldest months are January and February with an average of 34°F. The rainiest months in Jumunjin-eup are August, July, September, and June, with each month seeing an average of 8 inches of rainfall.