This is only true in Munich, where Oktoberfest starts in September and ends in October. In many towns in Germany, Oktoberfest is celebrated on one Sunday in October.
The first "Oktoberfest" took place on October 12, 1810: For the commemoration of their marriage, Crown Prince Ludwig (later King Ludwig I) and Princess Therese of Saxe-Hildburghausen (hence: "Theresienwiese") organized a great horse race (the marriage took place on October 12th, the horse race on October 17th, therefore there are different dates named as being the first Oktoberfest).
The Oktoberfest starts on the first Saturday after September 15 (2010 it will start on September 18) and lasts until the first weekend in October.
Oktoberfest is a 16- to 18-day festival held annually in Munich, Germany, typically starting in late September and ending in the first week of October.
The Oktoberfest takes place in Munich, Germany. It is held annually from late September to the first weekend in October.
October
Already answered atWhen_does_octoberfest_begin_2010
Oktoberfest does not occur in October in the first place. It actaully occurs at the end of the month of September.
Germany, in September
The Oktoberfest starts on the first Saturday after September 15 (2010 it will start on September 18) and lasts until the first weekend in October.
The Munich Oktoberfest will take place on Saturday, September 21st, 2013. The Oktoberfest will contain sales booth, carnival rides, beer tents and family days.
Oktoberfest is a 16- to 18-day festival held annually in Munich, Germany, typically starting in late September and ending in the first week of October.
The Oktoberfest takes place in Munich, Germany. It is held annually from late September to the first weekend in October.
September 20-22, 2013
October
The "official" Oktoberfest is in Munich (that's the one that you see on the TV) but most towns have their own celebrations as well. Stuttgart has the 2nd biggest Oktoberfest celebrations in all of Germany, and it's much more family friendly there (Oktoberfest in Munich is VERY intense).
Already answered atWhen_does_octoberfest_begin_2010
Annually. Oddly enough in September.
The Munich Oktoberfest ends on the first Sunday of October and usually lasts 16 days, starting on a Saturday. The date 2014 is September 20 - October 5. When October 3 is after the first Sunday in October, the festival is prolonged.