Weather is probably a major factor when you plan your trip to Sao Joao do Marinheiro, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually September and October, with an average temperature of 26°C, while the coldest months are June and July, with an average of 22°C. The rainiest months in Sao Joao do Marinheiro are January, December, February and March, with each month seeing an average of 222 mm of rainfall.