September 11th (Day 254) saw the 43rd Daily Record of the Year for Antarctic Sea Ice Extent. So far, 2013 would be the 3rd highest maximum of All Time behind 2012 and 2006.
2012’s maximum was 19.47713 million sq km
2006’s maximum was 19.35934 million sq km
2013’s maximum so far is 19.35119 million sq km
Click graph for bigger. Data is here.