The topic of a "super strong El Niño having formed" recently surged onto trending searches. According to the National Climate Center of the China Meteorological Administration, an "eastern-type super strong El Niño event" officially formed in September this year. This event has developed rapidly and with great intensity, and is expected to become the strongest El Niño event since systematic monitoring began. Faced with these claims, many people have raised questions: why does warming seawater in the equatorial Pacific affect weather far away? With El Niño here, will this winter be warmer? Will next summer be hotter? Are heavy rains, typhoons, and droughts all caused by it?
Why does El Niño cause the Pacific to "heat up"?
When a patch of ocean in the Pacific warms, weather around the world shifts accordingly, which is why El Niño has long been regarded as the Pacific's "climate remote control." So what does this "super strong El Niño" actually mean? You can think of it as the Pacific "running a high fever": a vast stretch of ocean in the central and eastern equatorial Pacific experiences abnormal warming of seawater, and this mass of "hot water" stirs up the global atmosphere, throwing weather patterns around the world into disarray.
Warm water and trade winds: the ocean-atmosphere interaction during El Niño
Under normal conditions, the Pacific resembles a basin of swaying bathwater: the surface of the tropical central and eastern Pacific is dominated by northeast trade winds and southeast trade winds. Under the influence of these trade winds, warm surface water accumulates in the western Pacific, causing sea surface temperatures in the western Pacific to rise and convection to become active, while the coast of South America experiences descending air due to upwelling cold water. This zonal circulation — rising air in the western Pacific and sinking air in the eastern Pacific — is known in meteorology as the Walker Circulation.
But when El Niño occurs, it is as if an external force suddenly tilts the basin in the opposite direction — weakened trade winds give rise to anomalous westerlies, and warm water from the western Pacific warm pool flows back toward the central and eastern Pacific. The bathwater along the South American coast, which should be cooler, becomes abnormally warm, triggering a weakening of the Walker Circulation. This imbalance sets off a chain reaction. Southeast Asia, which should be rainy, experiences drought, while normally dry South America suffers catastrophic flooding. Fish populations, unable to adapt to the excessively high sea temperatures in the central and eastern Pacific, die off in large numbers, leaving fishermen in Peru with nothing to catch. These fishermen noticed that El Niño appears every two to seven years, and that its impact on fishing is most pronounced around Christmas, so they named the phenomenon "El Niño," meaning the Christ child.
From 1972 to 1973, Peru's fishing industry suddenly collapsed. In some parts of the world, severe droughts led to massive crop failures, dried-up rivers, and water shortages, while in other places, torrential rains and devastating floods occurred. At the time, meteorologists were stunned that a series of climate anomalies appeared simultaneously around the globe, yet they had no idea that a strong El Niño event was behind it all. El Niño is like a "flu" in the Pacific — although it originates in the ocean of the central and eastern equatorial Pacific, it can stir up winds and rains across the entire world.
Just how strong is the strongest El Niño event?
Meteorological experts say the current El Niño event officially formed in September this year and is expected to become the strongest since systematic monitoring began. The label of "strongest in history" is not a baseless feeling — it is based on strict criteria. Just how strong is the strongest El Niño? According to meteorological satellite monitoring, the central and eastern equatorial Pacific has been in an El Niño state since May, with sea surface temperatures in the key Niño 3.4 region continuing to climb. From July to September, the three-month running average of the sea surface temperature index in the Niño 3.4 region exceeded 2.5°C, reaching the threshold for a super strong event. Meteorological authorities predict that over the next three months, sea surface temperatures in the central and eastern equatorial Pacific will continue to rise, peaking in late autumn and early winter, and this El Niño event will become the strongest since systematic monitoring began.
Zhao Junhu, chief forecaster at the National Climate Center of the China Meteorological Administration, explained: The National Climate Center primarily monitors the sea surface temperature index in the designated Niño 3.4 region. When the three-month running average of the index reaches or exceeds 0.5°C and persists for at least five months, it is classified as an El Niño event. The intensity of the event is defined by its peak — the maximum value of the three-month running average of the Niño 3.4 sea surface temperature index. If the peak reaches or exceeds 0.5°C but is less than 1.3°C, it is defined as a weak event; if it reaches or exceeds 1.3°C but is less than 2.0°C, it is a moderate event; if it reaches or exceeds 2.0°C, it is a strong event; and if it reaches or exceeds 2.5°C, it is a super strong event.
Sea surface temperatures in the central and eastern equatorial Pacific are expected to continue fluctuating upward, reaching the peak of this event around November to December. Its intensity is expected to surpass the three super strong events in history — those of 1982–1983, 1997–1998, and 2015–2016 — making it the strongest on record. This event is characterized by rapid development, high intensity, and significant climate impacts.
Does a super strong El Niño mean super high temperatures? No!
Since El Niño causes sea temperatures to rise, does a super strong El Niño automatically mean super high temperatures? Actually, no. A super strong El Niño acts like a powerful "global climate amplifier." It reshuffles the pathways of atmospheric energy and moisture transport, essentially pressing the "master switch" of global weather. But this is only a "warm-up" for climate anomalies — a super strong El Niño may trigger a series of extreme events regionally or globally, with some areas suffering catastrophic flooding, others experiencing drought and scant rainfall, and typhoon tracks and heatwaves all being rearranged.
Will this autumn and winter be cold or warm? Why is the "main event" next year?
El Niño's influence lies mainly in the atmosphere's response, which can be immediate or delayed depending on the stage of development. So what impact will this super strong El Niño event have on China's climate? Will extreme climate anomalies occur this autumn and winter, or even next spring and summer? Meteorological experts say that for China, El Niño's effects are more complex. Typically, during the development year of El Niño, areas south of the Yangtze River are prone to flooding; the number of typhoons forming in the western North Pacific tends to be above average, with formation positions shifting eastward and southward, and intensities tending to be stronger; and the probability of a "warm winter" in China is relatively high, though temperature fluctuations remain pronounced. In the decay year of El Niño, the flood risk in the Yangtze River basin is higher, while the number of typhoons forming is below average, and summer temperatures across most of China tend to be above normal, with heatwaves potentially more intense.