You can get an idea of this by looking at the comparison between the low ice at the beginning of September and the ice today from Cryosphere Today. (rabett.blogspot.ru)
Qu, X., and A. Hall, 2005: Surface contribution to planetary albedo variability in cryosphere regions. (ipcc.ch)
Others seem to prefer NSIDC data for monthly averages of both sea ice area and sea ice extent, or JAXA for daily data on sea ice extent, or daily sea ice area data from Cryosphere Today. (tamino.wordpress.com)