The 3 latest years were also the 3 lowest years in the Arctic for sea ice extent. Extent is the general area covered with 15 to 100% on the Arctic Ocean and adjacent seas.

Graph shows an average of the 3 latest years compared to the 2006–2015 baseline for Arctic sea ice extent. We see that winters are failing to build the same sea ice cover as in the decade prior to 2016. Spring melt, however, is slower in the last 3 than in the decade before. High summer melt is faster in 2016–18, early autumn melt is slower. And then the greatest anomaly compared to the baseline is October, which in recent years has failed to refreeze to the tune of almost a million km². The delayed ice–cover refreeze catches up in the first half of November.