Weather will likely play an important role when you plan your trip to Erechim, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually January and December with an average temp of 71°F, while the coldest months are July and June with an average of 57°F. The rainiest months in Erechim are October, May, September, and December, with each month seeing an average of 9 inches of rainfall.