If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Erechim: 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.