If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Riom-Parsonz: The hottest months are usually July and August with an average temp of 52°F, while the coldest months are January and February with an average of 22°F. The rainiest months in Riom-Parsonz are August, June, May, and July, with each month seeing an average of 8 inches of rainfall.