Oceans Reach Record Surface Temperatures Amid Strengthening El Niño

The global average surface temperature of oceans has hit a new record high as El Niño continues to strengthen, potentially reaching unprecedented levels. According to the European Union’s Copernicus Climate Change Service, the average sea-surface temperature across the world’s oceans reached 21.1 degrees Celsius (about 70 degrees Fahrenheit) on a recent Saturday. This temperature surpasses the previous daily record of 21.09 degrees Celsius set in March 2024.

Unexpected Timing of the Record

“Global ocean temperatures are typically highest in March and April, following the austral summer, yet this record has been reached in August,” stated Copernicus.

AccuWeather meteorologist Alex DaSilva explained that this record pertains to oceans outside the polar regions and indicates warming across multiple basins. “A lot of this has to do with El Niño,” said DaSilva. He emphasized that the Pacific Ocean’s vast area dominated by El Niño makes breaking records more likely during these periods. Additionally, the Atlantic basin has also experienced considerable warmth, contributing to the global record.

Copernicus previously reported that ocean temperatures outside polar areas stayed between 0.35 degrees Celsius and 0.73 degrees Celsius above the long-term average over the past three years. In June, temperatures were already at record levels, coinciding with the emergence of El Niño in the equatorial Pacific.

Understanding the Ocean Temperature Record

The all-time high average temperature recorded outside polar regions is 21.1 degrees Celsius (around 70 degrees Fahrenheit) as of August 22, 2026. This value surpassed the earlier August record of 20.98 degrees Celsius set in 2023. Samantha Burgess, a strategic lead for climate at the European Centre for Medium-Range Weather Forecasts, highlighted that this record signifies increasing stress on oceans. “El Niño is adding heat to the system, but it is doing so on top of decades of human-driven warming,” she noted. Rising ocean temperatures heighten risks to marine ecosystems and coastal communities, with marine heatwave days tripling since the early 1990s.

DaSilva mentioned that 2024 and 2023 follow closely on the record list. El Niño influenced late 2023 but shifted toward La Niña in 2024. “Typically, March and August are when the world’s oceans are at their warmest,” DaSilva observed. Despite this, he believes ongoing records in September are unlikely.

El Niño’s Potential Strength

El Niño represents the warm phase of the El Niño-Southern Oscillation (ENSO), a natural climate cycle affecting the tropical Pacific every two to seven years. During El Niño, the central and eastern equatorial Pacific waters warm, trade winds weaken, and tropical rainfall patterns shift eastward. These changes can influence weather and climate globally, according to the NOAA.

On August 13, NOAA’s Climate Prediction Center noted that El Niño was intensifying, with over a 90 percent chance of a strong event during Northern Hemisphere fall and winter through 2027. There is also a 69 percent probability of a historic event surpassing previous El Niño intensities back to 1950 during the October-December 2026 period.

DaSilva predicts another possible ocean record as the seasonal peak returns. “Depending on how strong El Niño gets this fall, we could break the world sea-surface temperature again next March,” he said, referencing the record set in March 2024 during the end of an El Niño period.