I won't let it stop me, but considering that it is still August as I write, it's premature to evaluate estimates of September's sea ice extent. On the other hand, it's fun and easy, and some parts make sense even at this early date.
Last May I made, with colleagues, some estimates for September 2011's extent. As usual, I also included some other forecasts for comparison. The NSIDC figure for August 29th is:
How the Universe Works: Season 3
7 hours ago