If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Barra Grande: The hottest months are usually September and October with an average temp of 82°F, while the coldest months are July and June with an average of 81°F. The rainiest months in Barra Grande are April, March, February, and May, with each month seeing an average of 10 inches of rainfall.