Weather is probably a major factor when you plan your trip to Wakura Onsen, but bear 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 temperature of 24°C, while the coldest months are February and January, with an average of 5°C. The rainiest months in Wakura Onsen are July, September, August and December, with each month seeing an average of 260 mm of rainfall.