Weather will likely play an important role when you plan your trip to Santa Catarina, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and May with an average temp of 70°F, while the coldest months are January and December with an average of 61°F. The rainiest months in Santa Catarina are September, June, August, and July, with each month seeing an average of 10 inches of rainfall.