If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Petite-Ile: The hottest months are usually February and January with an average temp of 78°F, while the coldest months are July and August with an average of 70°F. The rainiest months in Petite-Ile are January, February, March, and December, with each month seeing an average of 10 inches of rainfall.