A dangerous wave of wildfires is spreading rapidly across the tropics, and the Amazon rainforest is now facing a growing environmental and public health crisis. Fueled by severe drought linked to the El Niño climate phenomenon, aggressive fires are sweeping through vast parts of Brazil, filling major metropolitan areas with thick, toxic smoke and threatening fragile ecosystems that have already been severely damaged by previous fire seasons.
Unlike rapid-onset natural disasters such as tornadoes or severe thunderstorms, which can cause catastrophic destruction in a matter of minutes, El Niño influences global weather patterns over many months. The climate phenomenon can severely disrupt rainfall across vast regions of the globe, creating unusually dry conditions that allow agricultural and accidental fires to spread with terrifying speed. Scientists warn that the Amazon basin may be entering the initial stages of a prolonged, highly destructive fire season that could stretch deep into the coming year.
NASA Satellites Detect Surging Amazon Wildfires
Beginning in September 2026, high-resolution satellite observations revealed a sharp, alarming increase in active fires and heavy smoke emissions across the central and eastern portions of the Amazon rainforest. This growing environmental threat quickly appeared in several sophisticated monitoring systems, including NASA’s Fire Information for Resource Management System, the Global Fire Emissions Database, and NASA Worldview.
The affected geographic zone extends outward from the dense forests surrounding Manaus and Santarém—two vital commercial, economic, and transportation hubs in Brazil—stretching eastward toward the vast mouth of the Amazon River.
On October 12, 2026, the Moderate Resolution Imaging Spectroradiometer instrument aboard NASA’s Aqua satellite captured a striking, wide-angle image showing enormous, billowing plumes of dark smoke rising from numerous fires burning actively on both sides of the Amazon River.
At the time, thick and hazardous smoke had completely engulfed Manaus, the sprawling capital of Brazil’s Amazonas state. City officials reported dangerously polluted air conditions, with concentrations of fine particulate matter, known as PM2.5, soaring past 135 micrograms per cubic meter. These microscopic, pollutant-laden particles are capable of penetrating deep into human respiratory systems, posing severe, immediate health risks to vulnerable populations. These alarming measurements placed the city’s air quality firmly in the second-worst category of the regional air quality index.
The heavy smoke brought major disruptions to daily life in Manaus, a major urban center home to more than 2 million residents. Local schools were forced to shut their doors, public outdoor events were abruptly canceled, and children’s sports leagues suspended all activities as municipal authorities issued urgent warnings advising residents to remain indoors and avoid exposure to the hazardous environmental conditions, according to widespread news reports.
El Niño Is Triggering a Wildfire Domino Effect
According to Douglas Morton, an accomplished Earth system scientist at NASA’s Goddard Space Flight Center, the aggressive fires surrounding Manaus and Santarém are not isolated incidents; rather, they form part of a much larger, interconnected global pattern.
Morton describes the ongoing phenomenon as a devastating "cascade" of tropical fires directly driven by the widespread rainfall disruptions associated with the current El Niño cycle. This destructive sequence typically begins near the equator, where prolonged drought helps ignite severe peat fires in Indonesia. These subterranean fires burn slowly and intensely through carbon-rich organic material buried deep within the soil. As similarly dry conditions subsequently develop in other tropical zones, fire activity intensifies dramatically in the central and eastern sectors of the Amazon.
This overarching pattern is entirely unprecedented. Following the devastating 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 fires followed shifting rainfall patterns across the globe. Their crucial findings were eventually published in a comprehensive 2017 study. Researchers subsequently observed a remarkably similar sequence unfold during the 2023 climate cycle.
Now, the ongoing 2026 El Niño is producing the exact same dangerous progression across the southern hemisphere and tropical belt.
Indonesia has already experienced grueling months of severe drought, choking smoke, and destructive blazes that began as early as August. Throughout October, fast-moving wildfires destroyed hundreds of residential homes, while dense, opaque smoke blanketed entire islands on nearly every day of the month.
"Now, in the Amazon, we’re seeing the second domino in the cascade fall," Morton said, pointing specifically to the alarming surge in wildfire activity currently plaguing the Brazilian states of Pará and Amazonas.
Scientists Warn More Fires Could Spread Into 2027
The current surge in the Amazon basin may represent only a single stage of a much longer, protracted fire season.
Morton and his esteemed colleagues actively anticipate that wildfire activity will continue to expand northward through November and December 2026. The specific geographic regions currently most at risk include the Brazilian states of Roraima and Amapá, northern Pará, and neighboring portions of Venezuela, Guyana, and Suriname.
Following this northward progression, the destructive pattern is expected to shift sharply southward. By August and September 2027, worsening drought conditions and heightened wildfire danger are projected to reach their absolute peak across the southern Amazon regions of Brazil, as well as neighboring Paraguay.
One particularly troubling aspect of the ongoing crisis is the sobering reality that many of the forests currently under threat have already burned during past climate emergencies.
"It’s so striking — and frustrating — that this is happening all over again," Morton said, noting with concern that dense tropical forests previously impacted by the severe 2015 and 2023 El Niño events are once again catching fire as dry conditions return.
Wildfires are exceptionally destructive in tropical rainforests because the vast majority of the plant and animal species living within these ecosystems have not naturally evolved to withstand frequent or severe burning. Unlike other global biomes where fire plays a regular, regenerative ecological role, Amazonian forests suffer profound, long-lasting structural and biological damage when flames successfully move through their understories.
Furthermore, previous fires have left large parts of the forest highly vulnerable to future blazes. Trees that were partially burned or damaged during earlier meteorological events remain weakened, making the remaining vegetation far more susceptible to subsequent fires. Morton warned explicitly that some of the current active blazes could therefore burn with unprecedented intensity compared to historical fires.
He currently expects the dangerous fires near Manaus and Santarém to persist unabated until regional seasonal rains finally return, a meteorological shift anticipated around December 2026 or January 2027.
However, rural communities and municipal authorities located in regions farther to the north and south still retain a narrow window of opportunity to actively 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 rainforest is currently experiencing a profound fire emergency, natural lightning strikes are remarkably rarely responsible for igniting fires within Brazil’s dense tropical canopy.
The region is historically and climatologically so wet that natural lightning causes less than 1 percent of all recorded fires, according to Morton. This stark statistical reality means that nearly all of the fires currently spreading wildly through the Brazilian Amazon originated directly from deliberate or accidental human activity.
What makes the year 2026 particularly perilous, however, is the sheer severity of the ongoing drought conditions.
Official data released by Brazil’s National Institute of Meteorology revealed that total rainfall in Manaus dropped to an astonishing 95 percent below normal levels in August, followed by precipitation totals that remained 60 percent below normal throughout September.
These exceptionally dry environmental conditions have fundamentally transformed localized fires—which might otherwise have remained safely confined to managed agricultural or cleared plots—into massive, entirely uncontrolled wildfires.
Morton explained that many of the largest blazes currently consuming the region actually began as deliberately set fires utilized for routine land management practices, such as removing stubborn shrubs from cattle grazing land or clearing leftover crop residue from agricultural fields. Once the dry winds caught the flames, the fires rapidly escaped containment and pushed aggressively into the rainforest’s parched understory, the fragile layer of smaller vegetation growing directly beneath the towering canopy trees.
Recent satellite analysis suggests that approximately 50 to 70 uncontrolled wildfires are actively burning within the immediate vicinity of Santarém alone, according to Shane Coffield, an assistant research scientist at the University of Maryland who is currently stationed at NASA Goddard.
NASA Uncovers Hidden Fires That Satellites Are Missing
Despite the advanced capabilities of modern space exploration, the actual number of active Amazon wildfires may be substantially higher than standard, publicly available satellite monitoring systems currently indicate.
As part of a critical NASA Earth Action project, Coffield is meticulously studying high-resolution observations collected by the Visible Infrared Imaging Radiometer Suite, an advanced satellite instrument specifically designed to detect faint thermal heat signatures associated with active fires on the Earth’s surface.
His primary scientific goal is to identify hidden fires that routinely fail to meet the strict detection thresholds and technical requirements utilized in official FIRMS data products.
These additional detections, which researchers classify as "candidate fires," could eventually assist the scientific community in developing a far more comprehensive, accurate picture of true wildfire activity across the basin. Coffield actively plans to share the precise geographic locations of these hidden blazes with MapBiomas, a collaborative network comprised of universities, environmental nongovernmental organizations, and private technology companies dedicated to tracking fires and evolving land-use changes throughout the Amazon.
Initial findings from this targeted research suggest that conventional monitoring methodologies are consistently overlooking a significant number of ongoing 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 fires burning deep beneath a thick rainforest canopy remains a surprisingly difficult scientific challenge, even when utilizing sophisticated remote-sensing instruments orbiting high above the planet. Satellite sensors typically identify active wildfires by measuring infrared radiation emitted into the atmosphere, which reveals the intense heat generated by burning vegetation on the ground.
However, thick regional smoke, persistent cloud cover, and dense tree canopies can severely interfere with those delicate orbital measurements. Fires that burn slowly and creep quietly through the shaded understory are particularly difficult to detect because the thick green vegetation overhead successfully conceals their thermal heat signatures from space.
As a result, official satellite fire counts can occasionally drop precipitously even during periods when extensive, destructive 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 identifying and cataloging the numerous fires that existing operational monitoring systems routinely overlook, NASA researchers hope to provide scientists, conservationists, and local land managers with a much more accurate, realistic understanding of the unprecedented threats currently facing the Amazon rainforest as the El Niño-driven fire season continues to unfold.
