If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Musashino: The hottest months are usually August and July with an average temp of 77°F, while the coldest months are January and February with an average of 45°F. The rainiest months in Musashino are September, October, July, and June, with each month seeing an average of 8 inches of rainfall.