Not necessarily. Germany has no unified national school holidays such as other European countries. This is done mainly do avoid the extreme traffic jam exploits one is familiar seeing when everybody just needs to get the car and go on holidays on the same day. E.g. read more
Mostly August is indeed covered, with the notable exceptions of Bremen, Niedersachsen, Sachsen, which start their holidaying periods earlier. Saarland, Rheinland, Hessen only use the first half of August or less. But August is definitely a month were a good portion of the German population is on vacation. read more
School holidays are staggered, with the first Bundesländer at the end of June, while the last ones will only start a month later. read more
August: Average low 55° F / Average high 76° F; Events and Festivals in Germany during Summer. Germany’s festival season is in full swing for summer. With many festivities held outdoors, you can fully enjoy Germany's long, warm summer days. Between July and August, almost every German city organizes a city festival usually called a Stadtfest. read more