El Niño breaks its 2015 record as forecasters warn of a historic peak — and what it means for Pakistan

The Pacific Ocean has just passed a milestone that climate watchers have been expecting for weeks. Australia’s Bureau of Meteorology confirmed on Tuesday, 27 October 2026, that the warming at the heart of the current El Niño had beaten the highest weekly reading recorded during the powerful event of 2015. The new figure, 2.88 degrees Celsius above the tropical average for the week ending Sunday, 25 October, is the highest in the Bureau’s weekly records, which go back to 2008.

What makes it bigger is what the forecasters say comes next. Every international climate model assessed by the Australian Bureau points to further warming, with the event expected to peak in November or December. The United States National Oceanic and Atmospheric Administration, known as NOAA, gives an 83 per cent chance that October-to-December will be historically strong, stronger than any El Niño since reliable records began in 1950.

For Pakistan, the news matters directly. The 2026 summer monsoon finished 19 per cent short of normal for the country as a whole, and 51 per cent short in Sindh, according to the Pakistan Meteorological Department. Water stored in the country’s reservoirs started the dry season 6 per cent below the average of the past decade. What happens in the Pacific over the next two months will help decide whether the winter brings helpful rain for the wheat crop or more pressure on water supplies that are already stretched.

At a glance

What happened: Australia’s Bureau of Meteorology confirmed on 27 October 2026 that the Pacific’s weekly El Niño reading reached 2.88 degrees Celsius above the tropical average, beating the 2015 record of 2.78 degrees in its dataset going back to 2008.

Why it matters: Forecasters expect the event to strengthen further and peak in November or December, with NOAA giving an 83 per cent chance of a historically strong October-to-December period, while Pakistan is already feeling the effects through a short monsoon and low water storage.

What happens next: NOAA publishes its next update on 12 November, the peak is expected around December, and the effects on rainfall, heat and farming are likely to be felt well into 2027.

What the new record actually is

Forecasters watch a patch of the central equatorial Pacific called the Niño-3.4 region, comparing its surface water temperature with the seasonal norm and subtracting the general warming of the tropics. The result is called the relative Niño-3.4 index.

For the seven days ending 25 October, that index reached 2.88 degrees Celsius. The previous high in the Australian Bureau’s weekly dataset was 2.78 degrees, set in November 2015 during the last great El Niño. Earlier in October, a reading of 2.81 degrees for the week ending 11 October had already broken the 2015 mark, so the record has now fallen twice in a single month.

The atmosphere above the Pacific has responded strongly as well. The Southern Oscillation Index, which measures the difference in air pressure between Tahiti and Darwin, stood at minus 16.6 for the 30 days ending 25 October. Readings below minus 7 are associated with El Niño conditions, so minus 16.6 is far beyond the threshold.

One distinction matters. The Australian weekly record goes back to 2008, so beating it does not by itself make this the strongest El Niño ever measured. The longer monthly records, which allow comparisons back to 1950, have not yet been beaten. A single very warm week does not establish that a whole event is the strongest on record, but it does put this event in rare company, and the next two months will decide whether it joins the small group of truly historic El Niños.

Why forecasters think it will get stronger

The warnings about the coming months are unusually clear. NOAA’s assessment of 8 October put the chance of a historic October-to-December period at 83 per cent. By historic, NOAA means a three-month relative index of 2.5 degrees or more, a level no El Niño has reached since its records began in 1950. NOAA gave the same chance for strong to very strong conditions continuing through January to March 2027, and a 70 per cent chance of historic strength for November to January. Its next update is due on 12 November.

The World Meteorological Organization reached a similar conclusion by a different route. Its outlook of 21 October forecast central Pacific sea surface temperatures about 3.8 degrees above normal during November 2026 to January 2027, peaking around December, against a previous three-month record of 2.6 degrees set in late 2015. Its Secretary-General, Celeste Saulo, said the event could be unprecedented in strength, and the agency put the chance of El Niño lasting through February 2027 at nearly 100 per cent.

There is also a large reserve of warm water below the surface. NOAA reported earlier in October that parts of the eastern tropical Pacific held water more than 10 degrees warmer than normal at particular depths, a store of heat that currents can bring to the surface in the coming weeks.

How El Niño works, in plain English

El Niño is the warm phase of a natural climate pattern in the tropical Pacific. In a normal year, steady trade winds blow from east to west across the Pacific, pushing sun-warmed surface water towards Indonesia and Australia, where it piles up and feeds heavy rain.

Every few years, the trade winds slacken. The warm water that was piled up in the west spreads back east across the ocean, and the rain follows it. Clouds form over the central and eastern Pacific, while Indonesia and its neighbours turn drier.

NOAA has counted 22 completed El Niño events since 1950, roughly one every three and a half years, with most lasting about ten months and peaking in December. Only four have passed 2.0 on its index: 1982-83, 1991-92, 1997-98 and 2015-16. None has reached 2.5. The current event stood at 1.7 on the July-to-September reading, the second-highest for that season since 1950. Its strength does not decide exactly what will happen in any one country; it tilts the odds.

What it means for Pakistan

Pakistan sits at the western edge of the South Asian monsoon, so the link between El Niño and Pakistani rainfall is real but not simple. In past El Niño years, the median summer monsoon in Pakistan has run 28 per cent below normal, while the median winter rainfall from December to March has run 9 per cent above normal. Those are medians across many events, not promises.

This year, the summer deficit was deepest in the south. The monsoon finished 19 per cent short of normal for Pakistan as a whole, 51 per cent short in Sindh, while Punjab stayed within 4 per cent of normal, according to the Pakistan Meteorological Department. Water stored in reservoirs on 30 September stood 6 per cent below the average of the past decade. The Department has said the Indian Ocean Dipole, the Indian Ocean’s own east-west temperature see-saw, and El Niño may exert partly compensating influences over Pakistan this year.

Looking ahead, the signals point in two directions at once. The International Rescue Committee projects that Pakistan will experience drought conditions, with sudden glacier-melt floods in the northern mountains. The Famine Early Warning Systems Network described substantial rainfall deficits in Sindh, Balochistan and southern Punjab, and warned of a below-average kharif harvest in water-stressed areas. At the same time, it expects El Niño to favour above-average early winter rain in northern and central areas, including parts of Punjab. Rain at the right stage can help the wheat crop, but a better wheat season would not by itself replace the wages lost by farm workers during a poor kharif season. In short, El Niño is not itself a drought; it shifts the odds season by season.

Australia’s strange wet El Niño

Australia, where the record was measured, is living through an El Niño that is breaking the usual rules. El Niño has historically meant drier conditions in eastern Australia, yet the Insurance Council of Australia said on 29 October that 2026 is already on track to be Australia’s wettest El Niño year on record. October brought widespread storms across Queensland and the Northern Territory, and a storm in Central Australia damaged Alice Springs.

The Bureau’s long-range forecast, released on 29 October and covering November 2026 to January 2027, adds to the unusual picture. Daytime temperatures are very likely to exceed normal levels across almost the entire country, with the probability of above-average maximum temperatures above 80 per cent across most regions. Unusually warm nights are also expected to become widespread, at more than four times the normal likelihood. Hot nights matter because heat becomes more dangerous when temperatures stay high after sunset.

Rainfall is more complicated. Parts of western, central and eastern Australia are likely to see above-average rain between November and January, while Tasmania, parts of southern Victoria and the tropical north are more likely to be drier. The Bureau stresses El Niño is only one of several factors shaping Australian weather.

The insurance industry has noticed the gap between the old El Niño story and this year’s reality. The Insurance Council of Australia has urged households to check their cover now, before extreme weather arrives, because some insurers may place a temporary embargo on new policies, or on increases to cover, when extreme weather is imminent.

The rest of the world, and the heat risk

The World Meteorological Organization’s latest outlook maps out a world of opposite risks. Parts of East Africa are expected to see wetter-than-normal conditions during the October-to-December rainy season, raising concerns about flooding. Southern Africa faces an increased likelihood of dry conditions as its main rainy season begins in November. South-East Asia is expected to experience unusually warm conditions and rainfall shortages. India’s June-to-September monsoon ended 12.6 per cent below normal. Across the Americas, parts of the north-western United States and western South America are expected to see increased rainfall, while sections of Central America, the southern Caribbean and the Amazon face a heightened risk of drought.

Beyond rain, the most serious risk from a very strong El Niño is heat. In late October, the Climate Impact Lab at the University of Chicago updated its El Niño Heat Mortality Tracker. It projected about 373,000 additional heat-related deaths worldwide for October 2026 to March 2027, and roughly 857,400 for June 2026 to March 2027. The highest country-level risks for October to March were Nigeria, at about 56,000, India at about 55,200, Indonesia at about 29,300, Brazil at about 19,500 and Sudan at about 14,700. These are statistical model estimates, not individually confirmed deaths.

What to watch next

The next hard data point comes on 12 November, when NOAA publishes its next El Niño update. That will show whether October-to-December is on course for the historic strength NOAA gives an 83 per cent chance of reaching. If monthly measurements in November and December push past the highest levels seen since reliable records began in 1950, this event will rank among the strongest ever, alongside 1982-83, 1997-98 and 2015-16.

For Pakistan, the months to watch are December to March, when the winter rains arrive. A wetter-than-usual winter would help wheat in the north and centre, but the country will enter it with reservoirs below their decade average and with Sindh and southern Punjab already short of rain.

Frequently asked questions

What is El Niño?

El Niño is the warm phase of a natural climate pattern in the tropical Pacific. Every few years the trade winds slacken, warm surface water spreads east, and the rain follows it, changing weather patterns around the world. It usually lasts about a year and returns every two to seven years.

What record has just been broken?

Australia’s Bureau of Meteorology confirmed on 27 October 2026 that the weekly relative Niño-3.4 index reached 2.88 degrees Celsius for the week ending 25 October, the highest in its weekly dataset going back to 2008. The previous high was 2.78 degrees, set in November 2015.

Is this the strongest El Niño ever?

Not yet. The weekly reading has beaten the 2015 mark, but the monthly records going back to 1950 have not been broken. NOAA gives an 83 per cent chance that October-to-December will reach historic strength, a three-month index of 2.5 degrees or more, a level no El Niño has reached since 1950.

How does El Niño affect Pakistan?

El Niño tends to weaken Pakistan’s summer monsoon and slightly favour winter rain, but the link is not a fixed rule. In past El Niño years, the median summer monsoon ran 28 per cent below normal and the median winter rainfall ran 9 per cent above normal. This year’s monsoon was 19 per cent short nationally and 51 per cent short in Sindh, while Punjab stayed within 4 per cent of normal.

Will El Niño bring drought or floods to Pakistan?

Both risks exist in different places and seasons. Aid agencies project drought conditions for Pakistan overall, with sudden glacier-melt floods possible in the northern mountains. The Famine Early Warning Systems Network expects a below-average kharif harvest in water-stressed areas, but above-average early winter rain in northern and central areas, including parts of Punjab.

When will El Niño peak, and how long will it last?

Forecasters expect the event to reach its greatest strength in November or December 2026. NOAA expects strong to very strong conditions to continue through January to March 2027, and the Australian Bureau says El Niño conditions are likely to remain into the southern hemisphere’s autumn of 2027.

Conclusion

The Pacific has now beaten the peak of the great El Niño of 2015, something it has not done in the 18 years of Australia’s weekly records. The reading of 2.88 degrees Celsius for the week ending 25 October is a confirmed milestone. Forecasters are unusually united in what they expect next: more warming, a peak in November or December, and an 83 per cent chance that the season will be historically strong.

For Pakistan, the story is already partly written. The monsoon was short, Sindh was far short, and the reservoirs entered the dry season below their decade average. The winter ahead offers a chance of helpful rain in the north and centre, but it is a chance, not a guarantee, and it will not undo the losses of a poor kharif season. The next numbers to watch are NOAA’s update on 12 November and the December peak. If they confirm what the models now expect, the El Niño of 2026-27 will be remembered as one of the strongest since records began.

This article is for general information and education only. It is not legal or financial advice.

Sources

• https://www.abovethenormnews.com/2026/10/31/el-nino-2026-record-australia/ (Above The Norm News, 31 October 2026)
• https://www.insurancebusinessmag.com/au/news/catastrophe/wettest-el-nino-year-on-record-ica-urges-suminsured-checks-before-storm-season-595489.aspx (Insurance Business Magazine, 29 October 2026)
• https://smartwatermagazine.com/news/smart-water-magazine/el-nino-2026-27-flood-and-drought-signals-by-region (Smart Water Magazine, 23 October 2026)
• https://www.thepulsepaper.com/specials/el-nino-2026-pictorial (The Pulse Paper, 18 October 2026)
• https://www.rescue.org/uk/article/who-will-be-most-affected-el-nino-how-help (International Rescue Committee, accessed 1 November 2026)
• https://munaeem.org/2026/10/10/super-el-nino-2026-pakistan-food-crisis/ (Munaeem, 10 October 2026)
• https://particle.news/story/record-strong-el-nio-seen-driving-hundreds-of-thousands-of-heat-related-deaths (Particle News, 31 October 2026)