Global ocean temperatures at historic highs, La Niña collapse poised to push records further

Global sea surface temperatures are currently the fourth highest ever recorded for this time of year, raising renewed concerns among climate scientists as a developing El Niño event threatens to push marine heat to unprecedented levels.

According to data from the US National Oceanic and Atmospheric Administration (NOAA), global average sea surface temperatures in January 2026 remain significantly above the long-term average. While the current ranking is fourth highest historically for this date, climate scientists warn that a likely shift from La Niña to El Niño conditions later this year could intensify warming.

“There is a good chance for new record high daily sea surface temperatures later this year,” NOAA researchers said in a statement. The warming of sea surfaces is a key indicator of global climate patterns and has wide-ranging effects on weather, marine ecosystems and global heat distribution.

The previous record for the highest daily average global sea surface temperature was set in August 2023, when waters reached 21.1°C, according to the Copernicus Climate Change Service. That record followed a year marked by extreme heatwaves, marine life disruption, and intensified hurricanes — phenomena strongly associated with unusually warm oceans.

The transition from La Niña — a cooling phase of the Pacific Ocean that typically dampens global temperatures — to El Niño, which causes widespread ocean warming, often results in a significant jump in global heat. The World Meteorological Organization (WMO) has forecasted a moderate to strong El Niño event for mid to late 2026, a development that could accelerate global warming trends.

“Such temperature anomalies are not just statistical oddities — they represent real shifts in energy across the planet’s climate system,” said Dr Gavin Schmidt, Director of the NASA Goddard Institute for Space Studies, in a post earlier this month.

Persistent marine heatwaves and rising ocean temperatures contribute to coral bleaching, reduced oxygen levels, and threaten fish populations that underpin global food security. According to the Intergovernmental Panel on Climate Change (IPCC), over 90% of excess heat from global warming has been absorbed by the oceans.

Dr Karina von Schuckmann, an oceanographer with Mercator Ocean International, said in a statement that the oceans “have been accumulating heat relentlessly,” warning that “what we are observing now is a trajectory that is very difficult to reverse without sustained global action.”

The WMO reported on January 25 that 2023 was the hottest year on record globally, with ocean temperatures playing a key role in that milestone.

La Niña collapse begins

The tropical Pacific Ocean is undergoing a significant transformation, with the current La Niña collapsing faster than expected due to a powerful Westerly Wind Burst, reports Severe Weather Europe.

Meteorological agencies and climate researchers now forecast a rapid transition to an El Niño phase by summer, with global weather implications expected to follow into the 2026/2027 winter season.

Data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the US National Oceanic and Atmospheric Administration (NOAA) confirm the sudden weakening of cold sea surface anomalies across the central and eastern Pacific. This shift signals the end of a prolonged La Niña phase that has influenced global weather patterns since 2023.

“A powerful Westerly Wind Burst has swept across the tropics, erasing a lot of the cold anomalies and signalling the end of an era for the current atmospheric cycle,” researchers at Severe Weather Europe reported on January 29.

Recent satellite and oceanic analyses show subsurface warm water pools at depths of 100–250 metres expanding eastward. These rising temperatures are replacing the remaining cold anomalies at the surface, accelerating the breakdown of La Niña conditions.

Trade wind patterns have also reversed significantly. Westerly wind anomalies, particularly intense this January, have disrupted typical equatorial circulation and promoted rapid warming in the Niño 3.4 region — the key index used to define the ENSO (El Niño–Southern Oscillation) phase.

Forecasts from NOAA’s Climate Prediction Centre and the Copernicus Climate Change Service point to a high probability of El Niño conditions emerging by mid-2026 and reaching peak intensity during the 2026/2027 winter season. The most recent probabilistic model from the International Research Institute for Climate and Society (IRI) shows a clear consensus among leading forecasting systems on a warm ENSO phase within months.

“El Niño is likely to peak during winter, bringing its main impact during the 2026/2027 winter season across the United States, Canada, and also Europe,” said Severe Weather Europe.

Although La Niña’s atmospheric effects — including altered jet streams and rainfall anomalies — may linger into early spring, climatologists expect a decisive pattern reversal by mid-year. Historical analogues suggest similar ENSO transitions have led to pronounced shifts in seasonal weather, including wetter winters in the southern US, drier conditions in Australia, and increased storm activity in the eastern Pacific.

According to the Intergovernmental Panel on Climate Change (IPCC), such transitions in the ENSO cycle play a pivotal role in shaping global climate variability. With oceans absorbing over 90% of excess heat from global warming, changes in the Pacific basin are likely to amplify broader climate signals in the year ahead.