NASA detects strong El Niño forming

NASA has identified signs of a potentially historic El Niño event expected to peak this autumn, based on satellite observations. This phenomenon, which officially began in June 2026, is predicted to last until February 2027, according to the World Meteorological Organization (WMO).

El Niño could be strongest in decades

The U.S. Oceanic and Atmospheric Administration (NOAA) estimates an 83% chance that this El Niño will be the strongest since 1950. El Niño is part of the El Niño-Southern Oscillation (ENSO), a natural climate cycle involving changes in sea surface temperatures in the central and eastern Pacific.

Climate change and El Niño

According to the WMO, there is no evidence that climate change increases the frequency or intensity of El Niño events. However, it can amplify their effects by providing more energy and moisture to heat waves and heavy rains, potentially making their impacts more severe.

El Niño’s impact on global temperatures

El Niño typically raises global temperatures, increasing the likelihood of new temperature records. Farmers, firefighters, and coastal residents are already experiencing its effects, notes NASA. Sea surface temperatures in the eastern Pacific are about 1.7 °C above the long-term average and could rise further.

Satellite data tracks ocean changes

Josh Willis of NASA's Jet Propulsion Laboratory (JPL) reports that sea surface temperatures in the eastern Pacific are significantly higher than average. NASA uses Sentinel-6 satellites to measure ocean height every 10 days, complementing data from NOAA. These satellites help track changes in sea levels and temperatures.

Kelvin waves influence sea levels

Kelvin waves, which are warm water waves thousands of kilometers long, have contributed to rising temperatures and sea levels in the eastern Pacific. In early April 2026, these waves caused sea levels to rise by 30 to 40 centimeters in some areas of the eastern Pacific while dropping 15 to 20 centimeters around Indonesia and northern Australia.

Phytoplankton decline observed

NASA has mapped a vast band of warmer water spanning several million square kilometers from the Pacific to South America. The PACE satellite, launched in 2024, has observed the equatorial Pacific waters becoming noticeably bluer due to a decline in phytoplankton, which thrive in cold, nutrient-rich waters.

El Niño’s effect on marine life

During El Niño, weakened trade winds bring less nutrient-rich deep water to the surface, leading to a scarcity of phytoplankton and a bluer ocean. This change can trigger cascading effects throughout the marine food chain, impacting fish populations and ecosystems.

NASA continues monitoring El Niño

NASA plans to continue observing the El Niño phenomenon and its impacts using its satellites. Data collected since January indicate a Pacific already transformed by El Niño, with changes that could disrupt weather in many regions.

Expert explains El Niño and La Niña

Karine Durand, a weather and climate specialist, explains that El Niño and La Niña are climatic phenomena characterized by temperature anomalies in the surface waters of the equatorial Pacific, significantly influencing the global climate. The Earth's climate is warming, with Europe warming faster than other regions, according to assessments.