Taking into account the local weather in Yakushima is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually August and July with an average temp of 80°F, while the coldest months are January and February with an average of 58°F. The rainiest months in Yakushima are June, September, May, and July, with each month seeing an average of 14 inches of rainfall.