Extreme weather events have gone from unseasonal rarities to something we’ve come to dread every year, and now that we’re at the beginning of what’s been described as a Super El Niño, it seems the havoc is only set to continue.
But, what actually is an ‘El Niño’ event? Below is our complete guide to the weather system, how it works, and the places likely to be the most affected.
What is ‘El Niño’?
El Niño – which translates to ‘the boy’ in Spanish – is the term used to describe the warming of sea surface temperatures that occurs every two to seven years, typically concentrated in the central and eastern equatorial Pacific, off the western coast of South America, according to the Met Office.
The phenomenon has a counterpart – La Niña, or ‘the girl’ – which is characterised by cooler-than-average sea surface temperatures in the central and eastern equatorial Pacific. Together, El Niño and La Niña form the two opposite phases of the El Niño-Southern Oscillation, or ENSO, the biggest fluctuation in the Earth’s climate system.
How does an ‘El Niño’ event actually work?
More specifically, the phenomenon is linked to changes in the trade winds, according to the World Meteorological Organization, and an ocean process called upwelling plays an important role.
Typically, winds blow from east to west across the tropical Pacific (the region between the Tropics of Cancer and Capricorn). These trade winds push warm surface water towards the western Pacific, around Asia and Australia, according to National Geographic.
As this warm water moves west, cooler water from deeper in the ocean rises to the surface, along the coasts of countries such as Ecuador, Chile and Peru, and with it brings a dense bounty of nutrients. This is upwelling.
Not only is this process important for the health of fish – and therefore fishing industries – in these South American countries, but upwelling plays a major role in the global climate.
Warm ocean temperatures in the western Pacific support the rainy seasons in countries like Indonesia, while cool temperatures ensure dry conditions in South America. When El Niño occurs, no matter the intensity (weak, moderate, strong or very strong), the WMO states that it has far-reaching consequences across the planet.
So, what happens? Well, El Niño conditions are triggered when these crucial westward trade winds weaken, and the warm surface water, instead of swooshing towards Asia and Australia, moves eastward to the coast of northern South America.
Simply put, this weakens upwelling, so all that nutrient-rich cold water – vital for the fish populations that support industries and food supplies in Ecuador and Peru – doesn’t reach the surface. Fish populations can decline or migrate as their food supply changes, as Nat Geo puts it, and the economic impacts can be significant.
On top of that, warmer-than-usual ocean temperatures in the eastern Pacific alter atmospheric circulation, bringing increased rainfall and a greater risk of flooding to parts of coastal Peru and Ecuador. On the flip side, the shift in weather patterns can bring drought to Indonesia and parts of Australia, threatening agriculture and water supplies.
Then there are the impacts further afield on ‘global atmospheric circulation’ – essentially, the movement of heat and air around the planet – particularly during stronger El Niño events.
As the distribution of heat across the Pacific changes, El Niño can trigger uncharacteristically dramatic winters in North America, such as longer and colder stretches in California and Washington, as well as even heavier rainfall during the season in sub-Saharan Africa.
What makes this one a ‘super’ El Niño?
While the WMO rejects the use of the term ‘super’ El Niño, and instead labels the strength of the cycle as weak, moderate, strong or very strong, you’ll likely have heard the phrase thrown around.
Why? Well, because we’re on the brink of experiencing one. The organisation’s September-issued update confirmed an almost certain likelihood that El Niño conditions will continue throughout November and into February 2027, reaching a ‘very strong intensity’.
While the WMO says there is no evidence that climate change increases the frequency or intensity of El Niño events – something that is still being researched by scientists – we know that the cycle can amplify the impacts of a warming climate. For example, 2024 was the hottest year ever recorded, with human-induced climate change the primary driver and the powerful 2023-2024 El Niño boosting global temperatures.
Where in the world will be most affected?
The Guardian recently reported that a staggering 450,000 deaths could be caused by this El Niño by February as a consequence of the expected flooding, droughts and wildfires. This includes related deaths since June 2026, when the cycle began.
The publication produced a graph using data from Climate Impact Lab, which lists the following countries in descending order as the ten set to experience the most deaths because of this El Niño. They are as follows:
- Nigeria, 31,320 deaths
- Indonesia, 19,251
- Sudan, 17,430
- India, 15,670
- Brazil, 13,271
- DRC, 10,014
- Niger, 9,900
- Chad, 7,953
- Philippines, 6,504
- Vietnam, 5,566
The reality is that the extreme temperatures being amplified by this El Niño offer a glimpse of what could become the ‘new normal’ as the climate crisis intensifies. The Guardian reports that one researcher described the phenomenon as a ‘postcard from our future’, and the BBC says 2027 is ‘very likely’ to be the hottest year ever recorded.
What’s ‘Godzilla’ got to do with it?
While most of the talk is about temperature increases, colder temperatures can also be triggered by an El Niño event, and that’s precisely what might be in store for the UK.
Dramatically described by some as a ‘Godzilla’ El Niño, the one we’re beginning to experience is likely going to be the most powerful in living memory – but could also bring extreme cold, rather than just extreme heat.
Experts have said it’s too early to forecast this confidently, but there’s a possibility that El Niño has the potential to disrupt the polar vortex. It’s a high-altitude loop of cold winds which sit above the Arctic, but the Independent explains that the disruption of the polar vortex can weaken the jet stream which – hypothetically – would send freezing air south.
Right now, forecasts for the UK are a milder-than-normal early winter, with the extreme cold – if it arrives – likely to set in later in the season.
How might El Niño impact travel?
Throughout 2026 we’ve witnessed extreme weather, from drastic heatwaves in Europe to severe flooding in Thailand and Nepal, and if this El Niño is as strong as is currently being forecast, it’s likely to impact travel to affected destinations.
As a rule of thumb, if you’re heading somewhere that’s predicted to experience extreme weather, regularly check your flight or transport status before you begin your journey and keep an eye on local news outlets for the latest information.
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