Weather can make or break a roadtrip, so here's some data about year-round temperatures in Ofu Island to help you plan yours: The hottest months are usually March and April with an average temp of 82°F, while the coldest months are August and July with an average of 80°F. The rainiest months in Ofu Island are February, January, December, and November, with each month seeing an average of 13 inches of rainfall.