If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Ejisu: The hottest months are usually January and February with an average temp of 82°F, while the coldest months are August and July with an average of 76°F. The rainiest months in Ejisu are September, June, October, and May, with each month seeing an average of 8 inches of rainfall.