Brazil Braces for a Historic El Niño: Amazon Fire Risk and Southern Floods Loom This Spring

The air in São Paulo this week carried the particular tension of a season about to turn hostile. Brazil is entering its spring under the shadow of what meteorologists and scientists now describe as a potentially historic El Niño, with the latest bulletin from the national weather agency Inmet, a stark warning from one of the country’s foremost climate scientists, and a regional state of emergency in neighboring Peru all landing within the past 72 hours. The forecast for the September-to-November quarter paints a picture of a nation split in two: torrential rain in the South, and a perilous, fire-prone drought across the Amazon and the Center-West. As the country emerges from a year of relative environmental calm, the coming months threaten to test the limits of Brazil’s preparedness and the resilience of its people.

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Brazil Braces for a Historic El Niño: Amazon Fire Risk and Southern Floods Loom This Spring

São Paulo, Brazil — The warnings are converging with unusual urgency. Inmet’s newest bulletin, released on Wednesday, aligns with projections from the U.S. Climate Prediction Center (CPC) of NOAA, which now places a 90% probability on the phenomenon being "very strong." This is not a distant threat; the bulletin outlines specific, immediate risks for the coming quarter, from delayed rains in the Amazon to above-average rainfall in the country’s southernmost states. The convergence of these alerts has moved the conversation from academic projection to active public preparation.

A Spring Forecast of Extremes: The North-South Split

The defining feature of the upcoming spring, according to Inmet’s Bulletin No. 3, is a stark regional divergence. The Southern Region, particularly Rio Grande do Sul, along with parts of São Paulo and Mato Grosso do Sul, should expect rainfall volumes above the historical average. This brings the familiar threat of flooding to a region still scarred by past climate disasters. Conversely, the North and Northeast face a higher probability of a drier period, a trend that extends into Central and Southeastern Brazil, specifically hitting Mato Grosso, Tocantins, northern Goiás, Minas Gerais, and Espírito Santo.

This is the classic signature of a strong El Niño in Latin America: heavy rain and landslides in Peru and Ecuador, and drought across the Amazon, northeastern Brazil, and Central America. For Brazil, the bulletin warns that the combination of heat and prolonged drought in the Central and Northern regions significantly increases the risk of wildfires spreading. The situation could worsen if the start of the rainy season is delayed, a possibility Inmet considers likely for several areas. Temperatures are expected to remain above average across virtually the entire country, though Inmet does not rule out sharp temperature drops in September associated with cold air masses.

Scientists on Alert: 'The Strongest in More Than 100 Years'

The scientific community is not mincing words. Speaking at the Fourth Latin American Green Economy Forum in São Paulo on Thursday, Carlos Nobre, the renowned climate scientist who holds the Chair in Climate and Sustainability at the University of São Paulo’s Institute of Advanced Studies and is a retired researcher at INPE, told attendees that the El Niño now forming "promises to be the strongest in more than 100 years." Nobre, the architect of the Amazon tipping point theory, urged state governments to aggressively fight illegal fires between now and January, pointing a finger at organized crime as a persistent driver of Amazon burning even as deforestation rates have fallen.

His warning is backed by hard data. NOAA puts a 69% chance on this being the strongest El Niño since 1950, the full reach of its records. Forecasters expect sea-surface temperatures to exceed 2.9°C above normal in key regions of the Pacific. The event is still building, with the worst impacts likely to be felt in late 2026 and early 2027. The World Meteorological Organization (WMO) has warned that extreme weather is likely to increase in the coming months, a message that resonates deeply in a region where the last major El Niño, in 2023-24, pushed several Amazonian rivers to all-time lows, killed dolphins, and cut off communities that depend on river traffic.

The Amazon and Pantanal: A Delayed Rainy Season

For the Legal Amazon and the Pantanal, the spring quarter normally marks the transition between the dry season and the beginning of the rains. This year, a more intense and prolonged El Niño threatens to delay that change, leaving soils and vegetation drier for longer and increasing vulnerability to the occurrence and spread of fire. Projections from Censipam, the Center for Management and Operation of the Amazon Protection System, indicate below-average rainfall across a vast arc of the region, including Amapá, Roraima, Pará, Maranhão, Amazonas, and Acre, as well as northern Mato Grosso and parts of northern and central Tocantins and Rondônia.

This is the scenario that keeps environmental authorities awake at night. While NOAA researchers emphasize that more intense El Niño events do not necessarily mean more severe impacts, they do increase the likelihood. For communities in the Amazon, the delay of the rains is not an abstract statistic; it is the difference between a manageable dry season and a catastrophic one, where rivers become impassable, crops fail, and the smoke from fires blankets entire cities. The memory of 2024, the worst Amazon fire season in 20 years, is still fresh, and the forecast suggests the coming months could rival it.

Government Preparations: A Record Firefighting Buildup

In anticipation of this extreme drought, the Brazilian government has been bolstering its defenses. According to official environment ministry figures reported by Mongabay, funding for fire management in 2026 is 1.023 billion reais ($197 million), a 28% increase from 2025 and five times larger than in 2019. The environment ministry has also hired a record 4,410 additional federal firefighters for the 2026 fire season, up from 3,224 in 2024 and 4,358 in 2025, and has increased its fleet of water-bearing planes and helicopters.

João Paulo Sotero, director of deforestation and fire policy at Brazil’s environment ministry, has been candid about the stakes. "I'm not calm. I'm very alert," he said. "We are much better prepared [now] than we were in 2024 and 2025... we are prepared for the worst scenario." High-risk locations identified by the ministry include a new deforestation frontier in the south of Amazonas state and the area around the Gurupi Biological Reserve in Maranhão. The preparation is a recognition that, while the weather is a natural phenomenon, the fires that follow are often man-made. Carlos Nobre has been blunt on this point, telling Mongabay that 98% of fires in the Amazon are set by humans, not lightning or power lines. He has called for policies prohibiting the financial system from financing agricultural operations that use fire, a measure the ministry has discussed but not yet adopted.

Fragile Gains: The Context of 2025’s Record Low Fires

The coming challenge is made more poignant by the progress Brazil has recently made. According to MapBiomas’ annual fire report, roughly 7.7 million acres of forest burned in Brazil in 2025 — a 78.5% reduction from 2024, when fires affected an area larger than the state of Florida. This decline reflected more favorable weather after the previous El Niño-related drought ended, as well as environmental policy gains and more federal and community firefighting. Deforestation in the Brazilian Amazon between January and June 2026 totaled about 320,000 acres (1,295 sq km), down 38% from the same months of 2025 and the lowest first-half figure in a decade, according to INPE.

Yet the data also reveals a worrying undercurrent. Wildfire activity is not down everywhere. Imazon data reported by Inside Climate News shows the number of wildfires in the Amazon biome rose by about a third in the first months of 2026 even as clear-cutting slowed, and March 2026 deforestation rose 17% year on year. This suggests that while the government’s strategy of command-and-control enforcement is working against deforestation, the problem of fire is shifting and persistent. The gains of 2025 are real, but they are fragile, built on a foundation of favorable weather that is now set to turn against the country.

What is at Stake: The Amazon Bioeconomy and River Communities

Beyond the immediate threat of fire, the El Niño-driven drought expected until early 2027 could destabilize recent advances in the bioeconomy, a pillar in the fight against deforestation. According to Noticias Ambientales, the drought threatens to compromise essential crops such as cocoa, açaí, and guaraná, which are central to sustainable development strategies in the region. The bioeconomy is a central theme of the Latin American Green Economy Forum in São Paulo, sponsored by ApexBrasil and WWF-Brasil, which brings together political leaders, companies, and multilateral organizations to discuss climate strategy. The irony is stark: just as Brazil is positioning the bioeconomy as a viable alternative to deforestation, the climate is threatening to undermine its foundation.

For the river communities of the Amazon, the stakes are even more immediate. The most intense effects of the current event are expected between September and January, a period that will determine whether rivers remain navigable, whether fish stocks survive, and whether remote villages remain connected to the outside world. The 2023-24 El Niño offered a preview of this future, with rivers at all-time lows and communities cut off from supplies. The difference now is that the forecast is for an even stronger event, and the preparation, while improved, is being tested against a phenomenon that scientists say could be the strongest in a century.

What to Watch in the Coming Months

As Brazil moves deeper into spring, several indicators will bear close watching. The first is the onset of the rainy season in the Amazon and the Center-West; any significant delay will dramatically escalate the fire risk. The second is the behavior of the South, where above-average rainfall could lead to flooding in Rio Grande do Sul, a state that has already endured devastating floods in recent years. The third is the effectiveness of the government’s firefighting buildup, which will be tested in the new deforestation frontier in southern Amazonas and around the Gurupi Biological Reserve.

The regional context adds another layer of urgency. Peru’s declaration of a state of emergency covering 893 districts across 22 regions on Tuesday is a stark reminder that the impacts of this El Niño will be felt across the continent. In February, Peru had already declared a 60-day emergency in 179 districts after heavy rains. The current event is still building, and the worst is likely yet to come. For Brazil, the message from Inmet, from Carlos Nobre, and from the government’s own preparations is clear: this is not a drill. The spring of 2026 will be a test of the country’s resilience, its scientific foresight, and its political will to protect both its people and its forests.

This article was produced with AI-assisted research and editorial support. Sources: Cultivar Magazine/Inmet Bulletin No. 3, The Rio Times, Mongabay, MapBiomas, INPE, Imazon, Noticias Ambientales.

By Elena Vasquez, Staff Writer