What Happens in the Pacific Doesn't Stay in the Pacific

Somewhere along the equator, thousands of kilometres from Gulu, a patch of ocean is running more than 3°C warmer than it should. NOAA's September advisory puts the chance of a very strong El Niño this fall and winter above 90%, and the chance of a historic event, stronger than anything on record since 1950, at 75% for October to December. The World Meteorological Organization has taken the unusual step of saying the event will almost certainly last through February 2027. This is no longer a question of whether the Pacific will shift the weather. It is a question of who is ready when it does.

The reason this matters far from the Pacific is simple. That warm water changes where the atmosphere lifts and sinks, and the change travels. It dries out rainforests, starves fisheries, weakens monsoons, floods the Horn of Africa and lifts the sea along the California coast. The same signal that our earlier commentaries traced to Karamoja's heat and Elgon's slopes is now working on every inhabited continent at once. This piece follows it around the world, and then back home.

Heat-death hotspotsWetter-than-normal East AfricaDrought and fire riskMarine and fisheries stressCalifornia coastUganda

• 1 Niño 3.4 warm tongue: record ocean heat above +3°C
• 2 Peru: anchovy fishery suspended, seabirds and sea lions at risk
• 3 Brazil, Amazon: drought, low rivers and fire from September to January
• 4 California: Kelvin wave, king tides, atmospheric rivers
• 5 Nigeria and Sudan: largest projected heat death tolls (Nigeria 31,400)
• 6 East Africa: floods, Rift Valley fever, cholera, malaria
• 7 Southern Africa: below-normal rainfall, crop stress
• 8 India and Pakistan: failed monsoon, heat risk into 2027
• 9 Indonesia: peatland fires, drier season
• 10 Australia and the Coral Sea: bleaching and bushfire risk

The Ocean Feels It First

The first casualties are marine. Normally, cold, nutrient-rich water wells up along the coast of Peru and feeds the plankton that feeds the anchovies, which in turn supply much of the world's fishmeal. El Niño shuts that supply down. Peru's Ministry of Production has already suspended anchovy fishing in the north-central zone more than once this year, and NASA's ocean colour data shows chlorophyll in the equatorial Pacific well below normal. Fewer plankton means less food for zooplankton, fish, seabirds and marine mammals, and scientists warn that seals and sea lions are among those that starve in a super event. Elsewhere the pattern repeats: squid landings off California tend to collapse, and Indian Ocean tuna catches have been lowest after past strong events.

Heat adds a second blow. Marine heatwaves are expected to build across close to half the global ocean by the end of 2026, and coral reefs are the most exposed. Strong El Niño years have repeatedly driven mass bleaching across the tropical Pacific, the Indian Ocean, South-East Asia and north-eastern Australia, and the 2023 to 2024 event produced the fourth global bleaching episode on record. A reef that bleaches again before it has recovered rarely comes back to what it was. For the hundreds of millions who depend on reef fisheries and coastal protection, this is a food and safety issue before it is a conservation one.

The Amazon Is Already Burning

In the Brazilian Amazon, nearly 2.7 million acres had burned by the end of June, 318,000 more than the same period in 2025, before the dry season had even started in earnest. The 2023 to 2024 El Niño pushed several rivers to record lows and fuelled the worst fire season in two decades; more than 17 million hectares were affected in 2024. Brazilian technical agencies now warn that this year's drought could match or exceed 2015, and the number of Indigenous territories in severe drought rose from three to seventeen between June and July. Carlos Nobre, the scientist behind the Amazon tipping point work, expects the worst between September and January.

The detail worth holding onto is who lights the match. Nobre notes that almost all Amazon fires are set by people, through clearing, logging and farm burning, and a drought turns each of those fires into a conflagration. Brazil has responded with a record number of federal firefighters and a larger budget. That is the pattern the rest of this piece keeps returning to: the forecast is public, and the difference between a bad season and a catastrophe is what is done in the months before it arrives.

A Heat Toll Measured in Hundreds of Thousands

For the first time, researchers have put a number on what this El Niño could cost in lives through heat alone. The Climate Impact Lab at the University of Chicago estimates about 451,000 additional deaths worldwide between June 2026 and February 2027, compared with the same months in an average year from 1996 to 2025. Land temperatures are expected to run about 1.2°C above normal, with 44% more extremely hot days. The authors describe it as a preview of the heat that climate change would otherwise deliver in around twenty years, arriving before countries have had time to adapt.

The burden falls overwhelmingly on the Global South. Nigeria tops the list with a projected 31,400 deaths, and Nigeria, Indonesia, Sudan, India and Brazil together account for more than 97,000. These are modelled estimates, not a count of bodies, and the authors expect the total to rise because the event is forecast to persist into spring. But their central message is practical: heat warnings, cooling and hydration points, worker protections and extra health system capacity can prevent tens of thousands of these deaths if they are in place early. The heat is also lifting the planet itself. The WMO gives an 86% chance that a year before 2030 will surpass 2024 as the hottest on record, and says 2027 is the likeliest candidate.

India and Pakistan: A Failed Monsoon, Then the Heat

South Asia is where the El Niño signal has already turned into hard numbers. India's 2026 monsoon ended with a roughly 13% shortfall, its worst in more than a decade, and eastern and north-eastern India fell 26% below normal. Pakistan's Meteorological Department had flagged below-normal rainfall for most of Punjab, Sindh and Balochistan through the season, with warnings of moisture stress for crops and higher irrigation demand. Both countries also face a flood paradox, since warm conditions in the north accelerate glacier melt and flash-flood risk even as the plains stay dry.

The more serious question is what comes after. Pakistan's national forecasters expect a warmer-than-normal winter and note that El Niño years often bring earlier and more intense heatwaves, and India sits in the top five countries for projected heat deaths this season. Our reading, which is a judgement from these signals rather than a published forecast, is that the risk of prolonged heat does not end with the monsoon. It runs through a warm winter and into the pre-monsoon months of 2027, with wheat and other winter crops exposed as warmth shortens the grain-filling period. Cities that already recorded hundreds of heat deaths in a single week during Pakistan's 2024 heatwave should treat this as an early warning, not a distant scenario.

East Africa: Floods, Farms and Fever

For Uganda and its neighbours, El Niño works in two beats. June to September is often dry, which is why FEWS NET flagged below-normal rainfall for western Kenya and Karamoja this year. Then, with a positive Indian Ocean Dipole reinforcing the signal, the October to December rains turn heavy. ICPAC's outlook points to wetter-than-normal conditions across most of the Greater Horn, and names 1997 as an analogue year. In 1997, nearly 3,000 people died in floods across Ethiopia, Kenya, Somalia and Uganda, the deadliest El Niño flood event on record. Those rains matter more than they appear: they can supply up to 70% of annual rainfall in parts of Ethiopia, Kenya and Somalia and up to 40% in parts of Uganda, Rwanda, Burundi and Tanzania.

The agricultural effect is two-sided. Rain restores pasture and water, but flooding at the wrong moment destroys standing crops, washes out roads that carry produce to market, and collapses the storage and transport that smallholders depend on. Further south, the Southern African Development Community's outlook favours below-normal rainfall across Zimbabwe, Mozambique and southern Zambia, which puts maize at risk. All of this lands on a region where OCHA already counts 48.5 million people needing assistance and 40.4 million who are food insecure. Households that spent the dry months buying water and absorbing coffee and milk losses, as our last commentary described, now face the second half of the whiplash with less money than they started with.

Disease follows the water. IGAD and FAO have warned of a higher risk of Rift Valley fever, a mosquito-borne virus that moves through livestock and people, particularly in pastoral and agro-pastoral communities. The WHO is working with Kenya on readiness for cholera, typhoid and other waterborne illness as flooding contaminates drinking water, and heavy rain raises the odds of malaria, dengue and other mosquito-borne disease. Hotspots named by regional analysts include the Lake Victoria basin, the Tana River, the Juba and Shabelle catchments and dense urban areas such as Nairobi. For Northern Uganda, with its refugee settlements and thin health infrastructure, the Lake Victoria and Nile catchments are the neighbours to watch.

Where the Fires Will Be

Wildfire is the most visible sign of the drier half of the El Niño map. In Indonesia, roughly 230,000 acres burned in July alone, more than the previous six months together, and the meteorological agency had logged 5,019 hotspots by late July, with Sumatra and Kalimantan at highest risk, much of it on drained peatland that burns for weeks and chokes whole regions with smoke. Australia's Bureau of Meteorology expects below-average rain across southern and eastern states and a higher fire risk as temperatures rise. With the Amazon, that gives three of the planet's great fire theatres in simultaneous danger, which is exactly the kind of overlap that stretches firefighting capacity and aid budgets thin.

California: When the Sea Rises and the Moon Agrees

The Pacific's most direct delivery is to its eastern shore. A strong El Niño can lift sea level along the California coast by 15 to 30 cm, and a powerful Kelvin wave, a pulse of warm water moving north along the coast, is due to arrive in early October, adding as much as another 6 to 12 inches for weeks. Waves grow larger, rain arrives as atmospheric rivers, and the sea rises through water that has already swollen from heat. In December 2015, a strong El Niño storm produced individual waves above 63 feet off Mendocino.

This winter carries an unlucky coincidence. Tides swell and ebb over an 18.6-year lunar nodal cycle, and the amplifying phase is at or near its peak at the end of 2026, so the king tides around Thanksgiving and Christmas will stack on top of El Niño's higher sea. State coastal officials have flagged high-tide windows in November, December and January. NASA's sea level team found that a strong El Niño could produce up to five 10-year flood events in places such as Seattle and San Diego this winter, and up to ten by the 2030s in strong El Niño years. California declared a state of emergency in advance, and scientists say the highest sea levels on record are plausible. It is a rich-world example of what the rest of this commentary argues: the hazards are scheduled, and the question is whether the response is too.

What This Means for Northern Uganda

None of this is abstract in Gulu. The same Pacific warmth that is starving anchovies in Peru will, if the forecasts hold, deliver heavy rain to the Nile and Lake Victoria catchments over the next ninety days, and a global surge in food and fuel prices from failed harvests in South Asia, Southern Africa and Brazil. Post-conflict communities with limited savings absorb these shocks through the only buffer they have, which is each other, and that strains the social fabric we work to protect. The lesson from every region above is the same: forecasts have been accurate, specific and early, and the places that fare best are those that pre-agreed what to do when a threshold was crossed.

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What happens in the Pacific does not stay in the Pacific, and it does not wait for a response to be funded. The warning has been issued by NOAA, the WMO, ICPAC and a dozen national services, in unusually unambiguous terms. Between now and the end of the rains, the world will find out how many of those warnings became action in time.