El Niño hits 29.70C record in key Pacific zone

An intensifying El Niño pushed sea surface temperatures in a key Pacific monitoring region to a record 29.70C in September, the EU's Copernicus climate service said on 12 October 2026. Forecasters expect the weather pattern, which raises drought and flood risks and exacerbates global warming, to become the strongest ever recorded this year.channelnewsasia.com+1

The record matters because it was set before the episode's expected peak later this year. El Niño raises sea temperatures in the tropical Pacific, triggering weather changes that can increase the risk of drought and flooding, and adding to man-made global warming. Forecasters have watched the event intensify for months.aol.co.uk

What the record means

The Copernicus Climate Change Service said sea surface temperatures in a tell-tale El Niño monitoring region of the Pacific, known as Nino3.4, had reached an "all-time high" of 29.70C in September. This exceeded the peak temperatures of previously strong El Niño events of 1982/1983, 1997/1998 and 2015/2016, "underscoring the exceptional intensity of the current El Niño", the EU monitor said.

El Niño warms surface temperatures in the central and eastern equatorial Pacific Ocean, bringing worldwide changes in winds, pressure and rainfall patterns. It typically takes place every two to seven years and lasts around nine to 12 months, so the September reading arrived before the cycle's expected peak. Copernicus said it "cannot yet say that the current El Niño is the strongest ever recorded". As climate change raises ocean temperatures, it can make recent El Niño events appear stronger than past ones, complicating historical comparisons between decades.

Why Copernicus holds back

Copernicus said it had adopted a new index, which accounts for the warming of tropical oceans, and that this index suggested the current event is not yet stronger than past ones. But the values observed in September "point to an already exceptionally strong El Niño, especially given that the event has not yet reached its peak", Copernicus said.

Not all forecasters use the same scale to interpret El Niño. On Friday, Japan's weather agency said that El Niño conditions had reached their "strongest intensity on record", with temperatures in the phenomenon's monitoring area 4C above normal — a reading that sits alongside Copernicus's more cautious index-based comparison. As El Niño gathers strength, global average sea surface temperatures hit a record 21.05C for September, topping the previous high of 20.92C for the same month in 2023, according to Copernicus. Overall, the world experienced its second hottest September on record, with surface air temperatures averaging 16.27C, the EU service said.

Other agencies and ocean records

September was 1.63C hotter than the pre-industrial average, a period defined as 1850-1900. Nations agreed at the 2015 UN climate talks in Paris to keep global warming "well below" 2C above pre-industrial levels, while pursuing efforts to limit it to 1.5C. The United Nations declared in September that the long-term 1.5C target would be missed in a matter of years.

Copernicus director Carlo Buontempo said in a statement: "We are in a new run of months above 1.5C, and with a strong El Nino still intensifying it is likely to last into 2027." He added that crossing the Paris Agreement's long-term limit is only a matter of time, and that how far the world overshoots, and for how long, remains up to us.

Scientists say it is crucial to reduce greenhouse gas emissions from fossil fuels to limit the period of "overshoot" above 1.5C and bring temperatures back down as quickly as possible. The event is expected to peak later this year, with El Niño set to intensify before peaking in December, the UN has warned.