The largest beer festival in the world is Oktoberfest in Bavaria. Several other smaller beer festivals are held all over Germany all over the year. The 2nd largest beer festival in Germany and probably in Europe, is the Cannstatter Volksfest in Stuttgart. Its popularity increases and more and more people come from around the world to visit the festival every year. Many other places have beer festivals styled as "Oktoberfests", but taken on its own the name is generally taken to mean for the Munich event.
The second largest genuine Bavarian festival is the Gäubodenvolksfest in Straubing. The festival is similar like Oktoberfest but it has an own history and it is not a copy of the Oktoberfest.
Not called "Oktoberfest", but very similar in character, is the Cannstatter Wasen in Stuttgart which starts one week later and is the second largest fair in the world. Smaller beer festivals similar to the Oktoberfest are common in Germany and take place throughout the year in most bigger German cities. Some of them go on later into the night than the Oktoberfest.
Events and Holidays in Germany.
August is popular for beer festivals, wine festivals and theatre festivals. In the regions of Mosel and Rhine, the wine festivals are the favorites for visitors. The cities of Stuttgart, Hamburg, Mainz, Frankfurt or Aachen don’t stay behind; these are famous destinations for beer fans. Hope this helps! Take care.