Ocean temperatures in the Eastern Bering Sea

By Rick Thoman
Alaska Climate Specialist
Alaska Center for Climate Assessment and Policy
International Arctic Research Center/University of Alaska
Fairbanks

Ocean temperatures in the Bering Sea and North Pacific are nearly everywhere warmer than the 1991-2020 average for early May, with one glaring exception: the eastern Bering Sea.
Despite large and growing areas of open water in the northern Bering Sea, sea ice remains between St. Matthew Island and the Pribilofs. In fact, in the central Bering Sea the ice reached its furthest south extent of the entire 2024-25 season the first days of May.

From the climate perspective, it’s usually worthwhile to see how the current situation compares to the past. The graphic plots the eastern Bering Sea surface temperature departure from the 1991-2020 average for every month since January 1990.

There are a lot of interesting features in the graphic. Unsurprising, ocean temperatures prior to the early 2000s were mostly cooler than the long-term average. Between 2003 and 2007 water temperatures were frequently warmer than average, but this was followed by mostly cooler than average temperatures 2008 to 2015.

The prolonged warmth of 2016-2020 stands out, but since then it’s been more variability, with some months warm and some cool, though the comparatively cold ocean of last August, with all the storminess, really stands out. As for the current situation, this kind of plot helps us see that in the multi-decade context, what’s happening this spring is not especially unusual and does not provide much of a clue as to weather this coming summer.