Planning for the weather is a good way to make your trip to Tsukioka Onsen relaxing and enjoyable, especially when you're splurging. The hottest months are usually August and July with an average temp of 73°F, while the coldest months are February and January with an average of 38°F. The rainiest months in Tsukioka Onsen are July, December, January, and August, with each month seeing an average of 10 inches of rainfall.