If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Erechim: The hottest months are usually January and December, with an average temperature of 21°C, while the coldest months are July and June, with an average of 14°C. The rainiest months in Erechim are October, May, September and December, with each month seeing an average of 239 mm of rainfall.