Weather is probably a major factor when you plan your trip to Rio Branco, but bear in mind that cheaper options are usually available when the weather isn’t as good. The hottest months are usually September and August, with an average temperature of 27°C, while the coldest months are July and June, with an average of 25°C. The rainiest months in Rio Branco are March, February, January and December, with each month seeing an average of 341 mm of rainfall.