Weather will likely play an important role when you plan your trip to Fomboni, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually March and December, with an average temperature of 28°C, while the coldest months are August and September, with an average of 25°C. The rainiest months in Fomboni are January, February, March and December, with each month seeing an average of 228 mm of rainfall.