If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Sao Bento do Sul: The hottest months are usually January and February with an average temp of 69°F, while the coldest months are July and June with an average of 58°F. The rainiest months in Sao Bento do Sul are January, December, February, and October, with each month seeing an average of 10 inches of rainfall.