A dangerous wave of wildfires is spreading rapidly across the tropics, plunging the Amazon rainforest into a growing ecological and public health crisis. Fueled by a severe drought linked to the El Niño climate phenomenon, fast-moving fires are sweeping through vast regions of Brazil. The blazes are choking major metropolitan areas with dense smoke and threatening fragile forest ecosystems that are already deeply scarred and weakened by previous, recurring fire seasons.
Unlike rapid-onset natural disasters such as tornadoes or severe thunderstorms, which can unleash widespread destruction in a matter of minutes, El Niño exerts its influence over weather patterns across many months. This major climate phenomenon can profoundly disrupt normal rainfall distribution across vast geographic regions, creating unusually prolonged dry conditions that allow agricultural and accidental fires to spread with alarming speed. Scientists and climate researchers have issued stark warnings that the Amazon basin may only be entering the very beginning of what threatens to be a long, destructive, and deeply damaging fire season.
NASA Satellites Detect Surging Amazon Wildfires
Beginning in September 2026, high-resolution satellite observations revealed a sharp and alarming increase in active fires and massive smoke emissions spanning the central and eastern sectors of the Amazon basin. This growing conflagration quickly registered across multiple advanced monitoring systems, including NASA’s Fire Information for Resource Management System, the Global Fire Emissions Database, and the real-time visualization platform NASA Worldview.
The heavily affected territory extends from the dense tropical forests surrounding Manaus and Santarém—two vital commercial, economic, and transportation hubs in northern Brazil—eastward toward the wide mouth of the Amazon River.
By October 12, 2026, the Moderate Resolution Imaging Spectroradiometer instrument operating aboard NASA’s Aqua satellite captured a striking and troubling image showing enormous plumes of thick, dark smoke billowing upward from fires burning fiercely on both sides of the Amazon River.
At that time, an impenetrable blanket of heavy smoke had completely engulfed Manaus, the sprawling capital of Brazil’s Amazonas state. Municipal and health officials reported dangerously polluted air conditions, registering concentrations of fine particulate matter known as PM2.5 that exceeded 135 micrograms per cubic meter. These microscopic, soot-laden particles are small enough to penetrate deep into human lung tissue, posing severe, immediate risks to public health and respiratory safety. These alarming measurements instantly placed the city’s air quality into the second-worst category on the regional air quality index.
The suffocating smoke brought widespread, major disruptions to the daily life of Manaus, a metropolitan center home to more than two million residents. According to local news reports and municipal directives, authorities were forced to shut down schools, cancel public outdoor events, and suspend children’s athletic leagues and sports activities as public health advisories warned citizens to remain indoors and avoid exposure to the hazardous atmospheric conditions.
El Niño Is Triggering a Wildfire Domino Effect
According to Douglas Morton, a prominent Earth system scientist at NASA’s Goddard Space Flight Center, the destructive fires blazing around Manaus and Santarém are not isolated incidents; rather, they form a critical part of a much larger, interconnected global pattern.
Morton describes the unfolding situation as a devastating "cascade" of tropical fires directly driven by major rainfall disruptions associated with the cyclical return of El Niño. This destructive environmental sequence typically begins near the equator, where acute drought helps ignite extensive peat fires in Indonesia. These subterranean fires burn intensely through thick, carbon-rich organic material buried deep within the soil. As prolonged dry conditions subsequently develop and expand across other tropical zones elsewhere on the planet, fire activity simultaneously flares up in the central and eastern Amazon.
This overarching pattern is far from unprecedented. Following the devastating and historic 2015-2016 El Niño event, Morton collaborated extensively with researchers from the University of California, Irvine, Vrije Universiteit Amsterdam, and the University of Maryland to examine precisely how tropical wildfire activity followed shifting, drought-induced rainfall anomalies. Their crucial findings were formally published in a 2017 scientific study, and researchers observed a nearly identical destructive sequence unfold during the El Niño conditions of 2023.
Now, the ongoing 2026 El Niño cycle appears to be producing the exact same troubling progression across the globe.
Indonesia has already endured months of punishing drought, heavy smoke accumulation, and destructive wildfires that began as early as August. Throughout October, fast-moving wildfires destroyed hundreds of residential homes, while dense, acrid smoke blanketed entire island communities on most days, severely disrupting transportation and daily routines.
"Now, in the Amazon, we’re seeing the second domino in the cascade fall," Morton said, pointing directly to the surging number of uncontrolled fires raging across the Brazilian states of Pará and Amazonas.
Scientists Warn More Fires Could Spread Into 2027
The current surge in wildfire activity may represent only a single, early stage of a much longer and more punishing fire season across the South American continent.
Morton and his scientific colleagues anticipate that active fire conditions will continue to expand geographically northward through November and December 2026. The vulnerable regions at the highest risk during this upcoming phase include the Brazilian states of Roraima and Amapá, northern Pará, as well as parts of neighboring Venezuela, Guyana, and Suriname.
Following this northward shift, the dangerous pattern is projected to pivot southward. By August and September 2027, worsening drought conditions and extreme wildfire danger could reach their absolute peak intensities in the southern Amazon regions of Brazil, extending southward into Paraguay.
One particularly troubling aspect of the current environmental crisis is the realization that a significant portion of the threatened tropical forests has burned during previous climate events.
"It’s so striking — and frustrating — that this is happening all over again," Morton remarked, emphasizing that delicate forest tracts impacted by the severe El Niño episodes of 2015 and 2023 are once again falling victim to encroaching flames.
Wildfires are exceptionally destructive in tropical rainforest ecosystems because the vast majority of native plant and animal species living there have not evolved mechanisms to withstand or recover from frequent burning. Unlike other terrestrial biomes where periodic wildfire represents a normal, natural ecological process, Amazonian rainforests suffer severe, long-lasting structural and biological damage when flames manage to penetrate their canopies.
Furthermore, previous fires have left large parts of the forest significantly more vulnerable to future blazes. Trees that were partially burned, scorched, or structurally weakened during earlier climatic events remain compromised, making the surviving vegetation far more susceptible to ignition. Morton warned that some of the current active blazes could therefore burn with unprecedented intensity compared to historical fires.
While he expects the destructive fires burning near Manaus and Santarém to persist until seasonal rains finally return—historically anticipated around December 2026 or January 2027—communities situated in regions farther north and south still possess a narrow window of opportunity to mitigate the danger before local environmental conditions deteriorate further.
"Given the intensity of this El Niño, this really is the year for people to avoid burning at all costs," Morton emphasized.
Extreme Drought Turns Human-Started Fires Into Wildfires
Although the Amazon basin is currently experiencing a historic and severe fire emergency, natural ignition sources such as lightning are remarkably rare in Brazil’s tropical rainforest.
Under normal climatic circumstances, the region is exceptionally wet, meaning that lightning strikes account for less than 1 percent of all fires recorded in the Brazilian Amazon, according to Morton’s research. This empirical reality indicates that virtually all of the active fires currently sweeping through the rainforest originated directly from deliberate or accidental human activities.
What makes the 2026 season exceptionally perilous, however, is the unprecedented severity of the ongoing drought.
Data published by Brazil’s National Institute of Meteorology revealed that rainfall totals in Manaus plummeted by 95 percent below historical averages in August, followed by a decline of 60 percent below normal levels in September.
These extremely dry meteorological conditions have fundamentally transformed fires that might otherwise have remained safely confined to managed agricultural areas into fast-moving, uncontrolled wildfires.
Morton explained that a vast majority of the larger, more destructive blazes began as purposefully set agricultural fires utilized for routine land management practices, such as clearing shrubs and brush from established cattle grazing lands or removing crop residue from harvested fields. Once the intense flames escaped these containment zones, they rapidly surged into the rainforest’s parched understory—the dense layer of delicate vegetation growing directly beneath the towering canopy trees.
Detailed satellite analyses indicate that approximately 50 to 70 uncontrolled fires are actively burning within the immediate vicinity of Santarém alone, according to Shane Coffield, an assistant research scientist at the University of Maryland who conducts research at NASA Goddard.
NASA Uncovers Hidden Fires That Satellites Are Missing
Despite the extensive data provided by orbital instruments, the actual number of Amazon wildfires may be substantially higher than standard, real-time satellite monitoring systems are currently able to indicate.
As part of an ongoing NASA Earth Action project, Coffield is closely studying specialized observations collected by the Visible Infrared Imaging Radiometer Suite, an advanced satellite instrument specifically designed to detect thermal heat signatures associated with active fires on the Earth’s surface.
His primary research objective is to identify smaller, smoldering, or obscured fires that consistently fail to meet the strict detection thresholds and algorithmic requirements utilized in official operational data products.
These additional detections, classified by researchers as "candidate fires," could eventually assist the scientific community in developing a far more comprehensive and accurate picture of true wildfire activity across the basin. Coffield plans to share the precise geographical locations of these hidden blazes with MapBiomas, a collaborative, multi-institutional network of universities, non-governmental organizations, and technology enterprises that meticulously tracks fire occurrences and land-use changes across the entire Amazon.
Initial findings from this specialized tracking project strongly suggest that conventional operational monitoring methods are overlooking a surprisingly significant proportion of active blazes.
"For the area around Santarém, we’ve identified about 40 percent more fires than you’ll see in active fire counts from FIRMS," Coffield noted.
Detecting hidden fires burning beneath a thick rainforest canopy remains a formidable technical challenge, even for the most sophisticated remote-sensing instruments currently operating in orbit. Standard satellite sensors identify active wildfires by measuring specific wavelengths of infrared radiation emitted by burning vegetation.
However, thick atmospheric smoke, persistent regional cloud cover, and dense tree canopies can severely interfere with these sensitive radiometric measurements. Fires that burn slowly and creep along the shaded rainforest understory are particularly difficult to spot from space because the dense vegetation overhead effectively conceals their thermal signatures from orbital view.
Consequently, official satellite fire counts can occasionally register a sudden decline even while extensive, damaging burning continues unabated on the forest floor.
"On some of the smokiest days, we have very few detections from MODIS and VIIRS, and we know that isn’t right," Coffield stated.
By systematically identifying fires that existing operational monitoring systems routinely overlook, NASA researchers hope to provide scientists, policymakers, and local land managers with a far more accurate understanding of the unprecedented threats facing the Amazon as the punishing, El Niño-driven fire season continues to unfold.
