Heat released from ocean water into the atmosphere is driving up global temperatures and reshaping rainfall patterns, scientists explain.
El Niño is identified when sea‑surface temperatures in a pivotal region of the Pacific climb 0.5 °C or more above the long‑term average.
Current observations show those anomalies are already well above 2 °C above normal.
The Met Office’s latest forecasts indicate the deviation could surpass 3 °C later this year as the event approaches its peak.
Such a reading would be unprecedented in the instrumental record that extends back to 1950 and would likely rank as the strongest El Niño episode since the 19th century.
Below the surface, waters at roughly 100 m (330 ft) depth are running about 8 °C above mean in some locales, providing a warm‑water reservoir that could further amplify the phenomenon.
"We person galore months to spell portion this lawsuit continues to make and that's 1 of the reasons that we person accrued assurance that this volition berylliy a record-setting event," said Dr Zeke Hausfather, a clime idiosyncratic astatine Berkeley Earth, a US probe group.
Other modelling groups have suggested even larger anomalies, potentially reaching 4 °C above average.
"If that came to pass, 'It's not beyond the realm of anticipation to accidental this mightiness berylliy the strongest El Niño lawsuit successful 500 oregon adjacent 1,000 years,' Hausfather said, though it is intolerable to accidental for definite that acold backmost successful time."
Scientists caution that confirming such extremes for periods far beyond the observational record remains impossible.