The Pacific Region Used to Track El Niño Had Its Warmest Month on Record
The monthly sea surface temperature in the Pacific's Niño 3.4 region, the stretch of ocean used to monitor El Niño, reached an all-time high of 29.70 °C in September 2026, the Copernicus Climate Change Service reported Oct. 9, 2026.
The service said the September value exceeded the peak values of the previous very strong El Niño events of 1982/1983, 1997/1998 and 2015/2016, and that it underscores the exceptional intensity of the current event. The same bulletin records the September average sea surface temperature for the oceans between 60°S and 60°N as the highest on record for the month, at 21.05 °C, above the previous September record set in 2023.
Temperatures remained well above average across much of the tropical Pacific, where El Niño conditions are strengthening and are expected to intensify further in the coming months. Around Europe, sea surface temperatures were at record highs for September along the Atlantic coast and in the western Mediterranean, contributing to the unusual warmth over adjacent land.
The figures come from the service's ERA5 dataset, whose sea surface values are estimates of ocean temperature at a depth of about 10 meters, so they can differ from products that estimate temperature at other depths.
Global surface air temperature in September was 1.63 °C above the estimated pre-industrial average for 1850 to 1900, the second warmest September in the ERA5 record.
