Taking into account the local weather in Fanning Island is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually June and July with an average temp of 82°F, while the coldest months are January and February with an average of 80°F. The rainiest months in Fanning Island are May, April, March, and June, with each month seeing an average of 12 inches of rainfall.