This is obviuosly why though, not a great mystery...
"At the end of October, ice growth slowed, and at the end of the month extensive open water areas remained in the Beaufort, Chukchi, Kara and Barents seas. This region had the warmest ocean surface temperatures at the end of the melt season."
Still as GW said, at least the heat can radiate to the atmosphere allowing the seas to cool.
As can be clearly seen if you look, the Worlds Oceans are "Cooling" as we go into the negative cycles, the Arctic is one of the few places that had positive anomalies, but even here it has cooled down.
UNISYS Current Sea Surface Temperature Anomaly Plot - click to enlarge
Gray-Wolf wrote: