If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Mendoyo: The hottest months are usually March and November with an average temp of 80°F, while the coldest months are August and September with an average of 77°F. The rainiest months in Mendoyo are January, February, December, and March, with each month seeing an average of 11 inches of rainfall.