As the above image shows, the daily sea surface temperature between 60°South and 60°North reached 21°C on March 16, 2023, the highest temperature in the NOAA record that started in 1881.
This record high sea surface temperature reflects the change away from La Niña, as also illustrated by the images on the right.
Moving from the bottom of a La Niña to the peak of a strong El Niño could make a difference of more than half a degree Celsius, as illustrated by the image below, adapted from NOAA.
Even more dangerous are sea surface temperatures in the North Atlantic, which have been at record high for the time of year for some time, as illustrated by the image below.
North Atlantic sea surface temperatures are at their lowest around this time of year, in line with changes in the seasons. Last year, North Atlantic sea surface temperatures reached a record high of 24.9°C in early September.
As illustrated by the above image, sea surface temperature off the east coast of North America were as much as 13.8°C or 24.8°F higher than 1981-2011 on March 15, 2023.
This spells bad news for Arctic sea ice, which typically reaches its lowest extent in September.
