Planning for the weather is an important factor for making your trip to Cuiabá a success, especially when you're splurging. 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 Cuiabá are January, February, March, and December, with each month seeing an average of 10 inches of rainfall.