If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Rorschacherberg: The hottest months are usually July and August with an average temp of 62°F, while the coldest months are January and February with an average of 34°F. The rainiest months in Rorschacherberg are August, June, July, and May, with each month seeing an average of 7 inches of rainfall.