El Niño’s latest surge has rewritten the record books in one of the Pacific’s most closely watched hot spots, a fresh signal that the climate pattern is building unusual force, according to the EU’s climate monitor.
Forecasters worldwide have cautioned for months that this episode could rank among the strongest ever observed. Now, even before El Niño is expected to crest later this year, a major benchmark has already been surpassed.
El Niño is the warming phase of a natural climate cycle that lifts sea temperatures across the tropical Pacific. That heat can reshape weather patterns, heightening the chances of drought in some regions and flooding in others, while also stacking on top of human-driven global warming.
The Copernicus Climate Change Service reported that sea surface temperatures in Niño3.4 — a key monitoring zone used to track El Niño’s evolution — climbed to an “all-time high” of 29.70C in September.
Copernicus said that level overtook the peak readings recorded during the powerful El Niño events of 1982/1983, 1997/1998 and 2015/2016, “underscoring the exceptional intensity of the current El Niño”.
A dried-up rice field in Indonesia which is undergoing a prolonged dry season linked to El Niño
Still, Copernicus told AFP it “cannot yet say that the current El Niño is the strongest ever recorded”.
Because climate change has raised baseline ocean temperatures, recent El Niño events can look more intense than earlier ones, making direct comparisons across decades more difficult.
To address that, Copernicus said it has introduced a new index that factors in the broader warming of tropical oceans — and by that measure, the current El Niño has not yet surpassed previous episodes.
Even so, September’s figures “point to an already exceptionally strong El Niño, especially given that the event has not yet reached its peak”, Copernicus told AFP.
Measures of El Niño strength can vary, and not all forecasting agencies rely on the same scale.
Japan’s weather agency said Friday that El Niño conditions had reached their “strongest intensity on record”, citing temperatures in the phenomenon’s monitoring area running 4C above normal.
Record ocean temperatures
As El Niño continues to build, Copernicus said the global average sea surface temperature set a September record of 21.05C, exceeding the previous September high of 20.92C in 2023.
Copernicus also found that September ranked as the world’s second hottest on record, with average surface air temperatures of 16.27C.
That put the month at 1.63C above the pre-industrial average, defined as 1850-1900.
Under the Paris Agreement reached at the 2015 UN climate talks, countries pledged to hold warming “well below” 2C above pre-industrial levels and to pursue efforts to limit it to 1.5C to reduce the impacts of climate change.
In September, the United Nations said the long-term 1.5C goal would be exceeded within years.
“We are in a new run of months above 1.5C, and with a strong El Niño still intensifying it is likely to last into 2027,” Copernicus director Carlo Buontempo said in a statement.
He added: “Crossing the Paris Agreement’s long-term limit is only a matter of time. How far we overshoot, and for how long, is still up to us.”
Scientists say cutting greenhouse gas emissions from fossil fuels is essential to limit how long the planet stays in an “overshoot” above 1.5C and to bring temperatures back down as quickly as possible.
Experts have warned that this El Niño could help propel global temperatures to a new record in 2027.
El Niño heats surface waters in the central and eastern equatorial Pacific, setting off global shifts in winds, air pressure and rainfall.
The phenomenon typically emerges every two to seven years and persists for roughly nine to 12 months.
