The ocean tells only part of the story. The atmosphere must respond.
Pacific equatorial waters show accelerating warming with anomalies rising from +0.5°C to +0.7°C, meeting thresholds for El Niño conditions by traditional meteorological standards. Climate models project atmospheric response beginning July, predicting above-average rainfall in southern Brazil and drier conditions in northern and northeastern regions through spring.
- Pacific equatorial temperature anomalies rose from +0.5°C to +0.7°C in one week
- Niño 1+2 region near Peru reached +2.1°C, classified as very strong
- Climate models project atmospheric response beginning in July
- Southern Brazil expected to see above-average rainfall; north and northeast drier
- Center-north Brazil could experience temperatures 4°C above average in water-deficit areas
El Niño phenomenon intensifies in equatorial Pacific waters with temperature anomalies reaching +0.7°C, with atmospheric responses expected from July affecting rainfall and temperature patterns across Brazil.
The waters of the equatorial Pacific are warming faster than expected, and the signals are unmistakable. In the span of a single week in early June, temperature anomalies in the Niño 3.4 region—one of the ocean's most closely watched zones—jumped from 0.5 degrees Celsius above normal to 0.7 degrees, with absolute anomalies reaching 1.3 degrees. The data, released Monday by Meteored and drawn from the U.S. National Oceanic and Atmospheric Administration, suggests that El Niño is not merely developing; it is accelerating.
The Niño 3.4 region matters because what happens there ripples across the globe. Ocean temperatures in this stretch of the Pacific influence atmospheric circulation patterns that shape weather thousands of miles away. The warming trend that began in May has now strengthened enough that climate models are beginning to signal shifts in rainfall and temperature that could become visible by July. The atmosphere, in other words, may soon start to feel what the ocean has already begun to experience.
How to mark the official start of El Niño depends on which measuring stick you use. By the traditional methodology that meteorological centers have employed for decades, the Pacific has already met the threshold—anomalies have stayed above 0.5 degrees since mid-April, meaning May 2026 could already count as the first month under El Niño conditions. By a newer approach, designed to separate the El Niño signal from the broader warming of the world's oceans, the threshold was only crossed in recent weeks, and June may be the month that clinches it. Either way, the ocean is sending a clear message. But experts caution that the ocean tells only part of the story. For El Niño to be fully established, the atmosphere must respond. Temperature alone is not enough.
The warming extends beyond the Niño 3.4 zone. Near Peru's coast, in the Niño 1+2 region, anomalies have climbed to 2.1 degrees—a level associated with very strong events. Some of this heat may be driven by the Madden-Julian Oscillation, a system of tropical atmospheric variability that has been active over the western Pacific in early June. When this system's convective phase is in play, it weakens the trade winds and allows the ocean surface to warm more readily.
What comes next is written in the climate models, though with the uncertainty that always attends such forecasts. The European model ECMWF projects that by the second half of the year, southern Brazil will see above-average rainfall, with the possibility of extreme events. The north and northeast, by contrast, are expected to dry out, with drier conditions spreading into parts of the center-west and southeast as spring progresses. In the center-north of the country, temperatures are likely to run above average, particularly between October and November. In areas already facing water shortages, temperatures could climb as much as 4 degrees above normal, raising the risk of frequent heat waves, drought, wildfires, and stress on water supplies.
Yet the researchers offer a note of caution about reading too much into any single factor. While stronger El Niño events do increase the odds of the classic patterns associated with the phenomenon, regional impacts depend on interactions with other atmospheric systems. The intensity of ocean warming does not necessarily translate into proportionally stronger regional effects. The Pacific is warming, the models are watching, and July will be the month when the atmosphere begins to answer. What happens after that will depend on forces beyond the ocean alone.
Citações Notáveis
The temperature of the ocean is only one part of the story. For the phenomenon to be fully established, the atmosphere also needs to respond to the warming observed in the Pacific.— Meteored analysis
Although intense events increase the probability of classic El Niño patterns, regional impacts depend on interaction with other atmospheric phenomena and do not necessarily grow in the same proportion as ocean warming.— Climate analysis
A Conversa do Hearth Outra perspectiva sobre a história
Why does the Niño 3.4 region matter so much? There are other warm patches in the Pacific.
It's the one place where ocean temperature changes most directly drive global atmospheric circulation. What happens there doesn't stay there—it reshapes weather patterns across continents.
So when you say the atmosphere needs to respond, what does that actually mean?
The ocean can warm without the air above it immediately reacting. But once the atmosphere catches up, it starts to shift wind patterns, moisture movement, rainfall. That's when people on land actually feel it.
The article mentions two different ways of measuring El Niño. Why the change?
The older method just looks at raw temperature anomalies. The newer one tries to account for the fact that the entire ocean is warming due to climate change. You want to isolate the El Niño signal itself from that background trend.
And by that newer measure, we're just barely there?
Just barely. But the momentum is clear. If this warming holds, June becomes the official month. If it doesn't, we're still close enough that it's coming.
The projections for Brazil sound dire—heat waves, drought, wildfires. How confident are those?
The models agree on the broad pattern: wetter south, drier north and center. But regional impacts depend on other weather systems too. A strong El Niño makes those outcomes more likely, not certain. The uncertainty is real.
What should people in the north be watching for?
July. That's when the models say the atmosphere will start to respond. By then, we'll know whether the ocean's warming is going to reshape the weather or if something else will intervene.