‘Most Intense’ El Niño in Over 100 Years? How the Climate Event Could Impact the World

A powerful El Niño is developing in the tropical Pacific, with forecasters warning that the event could become one of the most intense in more than a century and trigger widespread weather disruptions.

The natural climate phenomenon is expected to add to the warming already driven by greenhouse gas emissions, potentially making 2027 the hottest year ever recorded.

El Niño Explained

El Niño is the warm phase of the El Niño-Southern Oscillation (ENSO), a recurring climate pattern centred in the tropical Pacific. Under normal conditions, trade winds push warm ocean water towards the western Pacific. When those winds weaken, the warm water moves eastward and rises to the surface, increasing sea temperatures.

That ocean warming influences atmospheric circulation, producing knock-on effects across the planet. Depending on the region, El Niño can bring increased heat and drought or heavier rainfall and cooler conditions.

The strength of the event matters because stronger El Niños generally increase the likelihood of more severe versions of these weather patterns.

An Exceptional Event in the Making

Sea surface temperatures in the Niño 3.4 region are already well above their long-term average. Forecast models suggest the anomaly could rise substantially by November. Some projections indicate a peak anomaly of around 3.9°C, considerably higher than the roughly 3°C anomaly recorded during the 2015 El Niño.

The event could therefore rival or surpass previous major El Niños, although scientists note that different indices measure the phenomenon in different ways. Using its Relative Oceanic Niño Index, NOAA estimates a 69% chance that the current event will be the strongest in its dataset, which dates back to 1950.

Why 2027 Could Break Temperature Records

El Niño temporarily raises global temperatures because the warmer Pacific releases additional heat into the atmosphere. Climate scientists Zeke Hausfather and Andrew Dessler estimate that the current event could add about 0.3°C to global temperatures.

Their calculations suggest global temperatures in 2027 could reach approximately 1.76°C above pre-industrial levels. That would put 2027 well above the current record-holder, 2024, if the projections materialise.

The significance extends beyond a single annual record. The spike would demonstrate how natural climate variability can temporarily push temperatures far above the underlying warming trend.

• Global Weather Impacts
• The consequences of a strong El Niño are likely to vary widely by region.

Some areas could face prolonged drought, higher temperatures and increased wildfire risks, while others may experience heavier rainfall and flooding.

Indonesia is already dealing with an intense dry season that has contributed to widespread fires, illustrating how El Niño can interact with existing weather conditions.

Scientists nevertheless caution that El Niño does not determine every regional weather event. Its effects depend on location, season and other atmospheric and oceanic factors.

Climate Change Adds to the Risk

The current El Niño is occurring on top of human-driven climate change, which is expected to amplify several of its consequences.

A warmer atmosphere can hold more moisture, potentially making heavy El Niño-related rainfall more extreme. In areas where the phenomenon causes drying, higher background temperatures can intensify soil moisture loss and drought.

Scientists remain divided over whether global warming directly causes stronger El Niño events. However, evidence from coral records, historical observations and climate models suggests the intensity of the cycle may have increased over the past century.

NOAA scientist Mike McPhaden has suggested that warmer tropical oceans could strengthen the feedback between ocean temperatures and winds, potentially allowing El Niño events to develop more quickly. If current forecasts hold, this year’s El Niño could offer an unusually stark glimpse of the hotter and more volatile climate that may become increasingly familiar in the decades ahead.