In early August 2026, Brazil witnessed a series of severe weather events, which included floods, tornadoes, hail, landslides and winds with speeds exceeding 100 km/h, in addition to the rare appearance of roller clouds. These extreme phenomena caused deaths and widespread destruction in southern states, São Paulo and Rio de Janeiro. Given this sequence, the central question is: what is the real influence of El Niño, already established in the Pacific Ocean, on these events?
Researchers consulted state that El Niño already has an impact on the Brazilian climate, especially in the southern region, but it is not solely responsible for all recent episodes, such as the strong winds that hit São Paulo and Rio de Janeiro.
“What we have observed is an anticipation of the potential influence of this phenomenon”, explained Lincoln Muniz Alves, researcher at the National Institute for Space Research (Inpe).
El Niño is a phenomenon characterized by the atypical warming of surface waters in the Pacific Ocean, near the coast of Peru. When its intensity increases, it modifies atmospheric circulation patterns and changes the rainfall and temperature regime in different parts of the globe.
Giovanni Dolif, researcher at the National Center for Natural Disaster Monitoring and Alerts (Cemaden), reinforces that the first effects of El Niño are already noticeable in Brazil.
“It is already influencing and favoring these severe storms and floods in the South, and the peak of these events should occur in a few months”, detailed Dolif.
First signs of El Niño appear in the southern region
Rio Grande do Sul was one of the most affected areas during the week of August 2, 2026, experiencing intense rain, hail and tornadoes, resulting from the passage of a robust cold front.
For experts, it is in the south of the country that El Niño’s performance is most clear during this period. Historically, the phenomenon contributes to increased precipitation in the region and can intensify episodes of extreme rainfall.
Still, scientists warn that El Niño does not act in isolation. High intensity meteorological events result from the combination of multiple atmospheric factors, which vary depending on each situation. The projections, however, raise concern.
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“Brazil needs to prepare for a greater probability of extreme events occurring by the end of the year”, warned Lincoln Muniz Alves.
How intense winds formed in São Paulo and Rio de Janeiro
If El Niño contributes to explaining part of the disasters in the South, experts do not point to it as the direct cause of the winds that devastated São Paulo and Rio de Janeiro.
The explanation for these events lies in distinct atmospheric dynamics. A mass of very low temperature air advanced from the south towards the southeast of the country. When encountering a mass of air warmer than usual for winter, which was moving in the opposite direction, it generated a shock.
The meeting of these air masses created the ideal conditions for the formation of a powerful gust front, capable of generating winds with destructive power. The intensity of this interaction is directly related to the temperature difference between the air masses involved.
It was this mechanism that caused trees to fall, structures to collapse, transport interruptions and accidents that resulted in deaths in both Rio de Janeiro and São Paulo.
Among the most notable phenomena during the passage of this cold front was the formation of so-called roller clouds, elongated structures that resemble cylinders moving in the sky.
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These clouds develop when warm, moist air quickly condenses into an atmosphere that features marked temperature contrasts and strong winds.
Pilot Passos witnessed the situation up close while flying between Rio de Janeiro and an oil platform at sea.
“It was impossible to measure its size, and the speed at which it approached was unbelievable. We had no idea that it was moving so quickly towards us,” he reported.
He described how everything happened in a matter of a few minutes.
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“We saw this formation. It was far from the platform. When we made the turn, it was already next to us. It was very fast. I had never seen anything like it”, added the pilot.
During the approach to landing on the platform, wind speeds increased from approximately 20 km/h to 100 km/h. Faced with danger, the team decided to return to Rio de Janeiro.
“Safety always comes first,” said the pilot.
With twenty years of experience and more than 8 thousand hours of flight, Passos observes changes in the weather pattern.
“The behavior is different. These are drastic and sudden changes. Even with the forecast, we end up surprising ourselves frequently,” he said.
Global warming worsens the intensity of extreme weather events
In the same week of August 2, 2026, other extreme events were recorded globally: floods and landslides in India, floods and an intense heat wave in China, thousands of deaths in Germany linked to extreme heat, a historic drought in England and blizzards and floods in Chile.
Studies indicate that global warming is already intensifying and increasing the frequency of several extreme weather events. In Europe, for example, researchers concluded that the likelihood of recent forest fires was increased due to the increase in the planet’s average temperature.
For Giovanni Dolif, an atmosphere with higher temperatures creates more unstable conditions and, consequently, more difficult to predict.
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“A hotter atmosphere becomes more turbulent and chaotic, which makes predictions even more difficult,” he explained.
The scientists’ conclusion is that El Niño, in fact, influences extreme events in the country, especially in the southern region. However, this influence manifests itself in a larger context: that of a planet in constant warming, where severe meteorological phenomena find more favorable conditions to become even more intense and destructive.