 Bernau includes the valley Bernauer Alb, a source stream of the Alb, and extends from 800 meters above sea level up to 1415 meters high.The municipality is bordered to the north by the municipality of Feldberg, in the east by Menzenschwand and the city of St. Blasien, in the south of Ibach, in the southwest of Todtmoos and on the west by the city of Todtnau in the district of Lörrach.The annual rainfall is 1919 mm.