Weather will likely play an important role when you plan your trip to Balneário Arpoador, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually February and January, with an average temperature of 25°C, while the coldest months are July and August, with an average of 19°C. The rainiest months in Balneário Arpoador are January, February, March and December, with each month seeing an average of 224 mm of rainfall.