If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Gloppen: The hottest months are usually July and August with an average temp of 53°F, while the coldest months are January and February with an average of 27°F. The rainiest months in Gloppen are October, December, September, and January, with each month seeing an average of 11 inches of rainfall.