The American Idol 12 audition cities and dates have not yet been announced. However, if you are interested in auditioning, expect the initial city auditions to take place in the summer of 2012. Then, Hollywood Week typically takes place around December, which would still be 2012 for the 12th season. Then, the final selection for the voting rounds will probably happen in January of 2013.
I will announce the cities and dates for the American Idol 2013 season when the show makes them available. That usually occurs around the end of the current season.
For those who have not auditioned, also be aware that the judges come on a later date than the initial city audition. If you get your golden ticket to see the judges, then you will return to that same city on a later date to appear in front of the judges.
American Idol 12 (2013) Audition Cities and Dates:
To Be Determined