For the Arctic, like the globe as a whole, 2016 has been exceptionally warm. For much of the year, Arctic temperatures have been much higher than normal, and sea ice concentrations have been at record low levels.
The Arctic’s seasonal cycle means that the lowest sea ice concentrations occur in September each year. But while September 2012 had less ice than September 2016, this year the ice coverage has not increased as expected as we moved into the northern winter. As a result, since late October, Arctic sea ice extent has been at record low levels for the time of year.