Though there’s been no official announcement yet, the Times-Picayunne reports that HBO is currently eyeing a Sepetember 23rd or 30th return for Treme. It will likely be paired with Boardwalk Empire, the Steve Buscemi series. The first two seasons of Boardwalk have kicked off in September 2010 and 2011. Treme had previously kicked off in April.
HBO ordered 10 episodes for the third season of Treme and they were produced between November 2011 and May 2012.