If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Costa Careyes: The hottest months are usually May and July with an average temp of 81°F, while the coldest months are January and February with an average of 76°F. The rainiest months in Costa Careyes are September, August, October, and June, with each month seeing an average of 8 inches of rainfall.