Taking into account the local weather in Ten-ei 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 69°F, while the coldest months are January and February with an average of 33°F. The rainiest months in Ten-ei are July, September, August, and June, with each month seeing an average of 10 inches of rainfall.