El Niño sets temperature record in key Pacific zone, says EU monitor

An intensifying El Niño broke a temperature record in a key zone of the Pacific in September, the EU's climate monitor said Monday, another sign the weather pattern is gaining exceptional strength.

Global forecasters have been warning for months that this El Niño would likely become the strongest ever observed, and the latest record has tumbled even before the episode's expected peak later this year.

The warming phase of a natural climate cycle, El Niño raises sea temperatures in the tropical Pacific, triggering changes in weather that can increase the risk of drought and flooding, and exacerbate man-made global warming.

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 29.70 degrees Celsius last month.

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.

But in a statement to AFP, 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.

Copernicus said it had adopted a new index, which accounts for the warming of tropical oceans, that 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 told AFP.

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 4 degrees Celsius above normal.

Record ocean temperatures As El Niño gathers strength, global average sea surface temperatures hit a record 21.05 degrees Celsius for September, topping the previous high of 20.92 degrees Celsius for the same month in 2023, according to Copernicus.

Overall, the world experienced its second hottest September on record, with surface air temperatures averaging 16.27 degrees Celsius, the EU service said.

September was 1.63 degrees Celsius 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" 2 degrees Celsius above pre-industrial levels, while pursuing efforts to limit it to 1.5 degrees Celsius, in order to limit the effects of climate change.