Highlights The September 2013 Arctic sea ice minimum extent was 5.10 million km2. This was 1.69 million km2 greater than the record minimum set in 2012, but was still the sixth smallest ice extent of the satellite record (1979-2013). The amount of first year sea ice continues to increase, accounting for 78% of the ice cover in March 2013. A satellite-derived, Arctic Ocean-wide decrease in sea ice freeboard, from 0.23 m in March 2011 to 0.19 m in March 2013, implies a 0.32 m decrease in ice thickness, from 2.26 m to 1.94 m.