If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Cuiaba: The hottest months are usually September and October with an average temp of 84°F, while the coldest months are July and June with an average of 78°F. The rainiest months in Cuiaba are January, February, March, and December, with each month seeing an average of 10 inches of rainfall.