Super El Niño breaks sea temperature record weeks ahead of expected peak

El Niño has continued to strengthen to what some scientists are calling "unprecedented levels", weeks before its expected peak in December.

Several key measures are now in record territory.

It comes after scientists declared a new record for daily sea surface temperatures in the central-eastern Pacific in September, exceeding the previous record set during the very strong El Niño of 2015.

Temperatures above 30C have also been recorded for the first time in parts of the tropical Pacific, while record sea-surface temperature anomalies and exceptional subsurface warmth have been observed.

These measurements come from the region of the equatorial Pacific used to monitor El Niño.

El Niño is a naturally-occurring pattern, which happens about every two to seven years and tends to last for around a year.

However, the Pacific is also warming due to human-induced climate change and this is starting to mask the strength of the natural warming during El Niño.

To remove this additional warming signal, Australian and US official forecasters are now using a Relative Ocean El Niño Index (RONI), to enable better comparison to historical events.

Using that measure, the BOM's average weekly data - while only going back to 2008 - is significant as it now exceeds levels during the record-breaking December of 2015 .

"We are currently witnessing an El Niño event that is unprecedented in the historical record," Dr Zeke Hausfather, a climate scientist at Berkeley Earth, told the BBC.

The warmth across the Pacific now extends well beyond the tropical region normally used to monitor El Niño.

Comparisons with previous major events in 1972-73, 1982-83, 1997-98 and 2015-16 show much more widespread ocean warmth across the Pacific and into the Gulf of Mexico.

Part of this reflects the long-term warming of the oceans but scientists say it is not the whole story.

"The strength of El Niño this year is spilling out of the traditional El Niño region," Dr Hausfather said.

Developing El Niño becomes strongest on record weeks before expected peak

What is El Niño and why could it mean record temperatures?

The World Meteorological Organization (WMO) says there is currently no evidence that climate change is making El Niño events stronger or more frequent , external . However, it remains an active area of scientific research.

What is clearer is that El Niño releases additional heat from the oceans into the atmosphere.

Historically, global temperatures during El Niño years are typically higher than during neutral years.

Combined with human-driven climate change, that extra heat is expected to help make 2026 one of the warmest years on record, with unusually high global temperatures likely to continue into 2027.

Although the most widespread impacts are expected later this year and into 2027, El Niño's influence is already being felt across parts of the world.

The strength of an El Niño does not automatically determine the scale of impacts in any one location. Regional effects can vary considerably from one event to another.

However, some common patterns are emerging when compared with previous super El Niños.

During the 1997-98 event, severe drought across south-east Asia contributed to extensive peat and forest fires, while parts of East Africa experienced devastating floods.

The event also helped make 1998 the warmest year on record at the time.

A similar pattern developed during the 2015-16 El Niño.

Severe drought and wildfire activity returned to parts of south-east Asia, while southern Africa experienced one of its worst droughts in decades, triggering a major humanitarian crisis.

Another recurring signal is tropical cyclone activity. Strong El Niño events typically suppress Atlantic hurricanes while boosting activity across parts of the Pacific, a pattern that has also been observed during 2026.

The World Meteorological Organisation says drought and flood-related disruption is already being reported in several regions, with growing concerns over food security in parts of East Africa and the Asia-Pacific.

Forecasts from both the European Centre for Medium Range Weather Forecasts and the US National Oceanic and Atmospheric Administration indicate El Niño is likely to peak in December.

Dr Hausfather said the latest projections were "astonishing" and are likely to set new records "by a remarkable amount".

What questions or concerns do you have about El Niño?