Weather will likely play an important role when you plan your trip to Jiseiji 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 January and February, with an average of 7°C. The rainiest months in Jiseiji Onsen are July, June, August and September, with each month seeing an average of 272 mm of rainfall.