El Niño Reaches Record Levels Worldwide

El Niño is intensifying ahead of its projected December peak, with multiple indicators reaching records. BOM data show that weekly average surface water temperatures in the central Pacific are the highest recorded. September also produced a daily temperature record in the central-eastern Pacific, surpassing the mark associated with the powerful 2015 event. Some tropical Pacific waters have exceeded 30C for the first time, alongside exceptional warmth below the surface and record temperature departures at the surface.

The broader warming of the oceans from human-induced climate change makes comparisons with older El Niños more difficult. Official forecasters are therefore using the Relative Ocean El Niño Index, or RONI, to separate that underlying warming signal. BOM’s weekly RONI record begins in 2008, and the latest reading has moved above the level reached in December 2015. Compared with major episodes in 1972-73, 1982-83, 1997-98 and 2015-16, unusually warm water now covers a wider area of the Pacific and reaches into the Gulf of Mexico.

El Niño generally develops every two to seven years and usually persists for about a year. It transfers extra ocean heat into the atmosphere, and its combination with human-driven warming is expected to place 2026 among the warmest years recorded. Unusually elevated global temperatures are likely to extend into 2027. Effects already include drought and flood disruption in several regions, along with food-security concerns in parts of East Africa and the Asia-Pacific. Strong events also tend to reduce Atlantic hurricanes while increasing cyclone activity in portions of the Pacific, a pattern observed during 2026. For Simi Valley families, the record strength alone does not establish the severity of local effects because regional outcomes differ between events.