Weather is probably a major factor when you plan your trip to Seomyeon, 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 74°F, while the coldest months are January and February with an average of 39°F. The rainiest months in Seomyeon are July, August, June, and September, with each month seeing an average of 10 inches of rainfall.