The probability of record-breaking global heat has grown after central Pacific temperatures reached 3.05C, exceeding the late-November 2015 high of 3.02C relative to the 1991–2020 baseline. That measured warmth comes months before the event’s expected peak and increases the chance that the year could finish among the hottest on record.
The Story in Pictures
Climate scientists track both the raw tropical Pacific anomaly and the Oceanic Niño Index, a 30-year rolling average designed to account for underlying human-driven warming. Both indicators draw on data maintained by the US National Oceanic and Atmospheric Administration; the plain temperature anomaly has already passed the 2015 mark while the ONI sits just under that earlier peak.
An ensemble average of 14 climate models assessed by Zeke Hausfather now projects a November–December peak close to 4.0C. Hausfather described the projection as "mind-blowing", and others have labelled it "Godzilla-level." Scientists note that any ONI above 0.5C qualifies as El Niño, readings above 2C are classed as a "very strong" or "super" event, and some researchers estimate this could be the largest El Niño in at least 1,000 years.
Researchers warn that this El Niño is unfolding on top of an atmosphere already warmed by fossil-fuel emissions, a combination that amplifies impacts on heat, water and food systems. Professor Friederike Otto of Imperial College London said, "This event is a huge redistribution of energy in the climate system and is dangerous because it is unfolding on top of a much warmer, human-influenced climate system." She added, "So, in many places around the world we will see never-before-experienced heat extremes, with all their consequences on health, food security and water stress."
Signs of those consequences are visible now. Indonesia has reported record wildfires and hazardous air pollution, India has experienced curtailed monsoon rains, and drought across Central America and the Caribbean is damaging crops and slowing Panama Canal traffic. The World Food Programme warned in August that El Niño’s effects could push about 50 million people into acute hunger and push food prices higher.
El Niño typically shifts rainfall and storms: Peru and Chile are facing intense rain and flooding, the Horn of Africa is vulnerable to heavy downpours, and the southern United States is expected to see strong winter rains. Southern hemisphere summer projections point to hotter, drier conditions in parts of Australia and southern Africa, increasing the risk of wildfires and drought. Tropical cyclone activity is also expected to change, with Pacific typhoons likely to be more intense while Atlantic hurricanes are generally suppressed; notably, none has formed in the Atlantic so far this year.
International bodies are preparing for an elevated threat environment. The UN World Meteorological Organization has launched its largest mobilisation in its 50-year history to help national services deliver forecasts, and UN secretary-general António Guterres warned the world is "in the danger zone of extreme weather." Researchers say the pairing of an oversized El Niño and long-term global heating raises the potential for unprecedented weather patterns, complicating preparedness for vulnerable communities.
The immediate course is to monitor model updates as the Pacific continues to warm toward the projected November–December peak, and for governments and relief agencies to adjust forecasts and contingency plans accordingly.
