The smoke that covered Manaus throughout this Monday (12) persisted because the atmosphere had little capacity to disperse pollutants, according to meteorologist Andrea Ramos. The situation kept the capital of Amazonas with the worst air quality in Brazil until 6 pm, according to data from the international platform IQAir.
Images taken during the afternoon and sent to g1 show the horizon covered by smoke in different parts of Manaus. One of the records, made by a resident of Conjunto Castanheiras, in the Gilberto Mestrinho neighborhood, shows little visibility.
The air quality was classified as “unhealthy” by the platform. At around 5pm, the Air Quality Index (AQI⁺) reached 181, after reaching 195 earlier. In the late afternoon, the concentration of fine particles PM2.5 was 97.9 micrograms per cubic meter (µg/m³).
According to IQAir, the concentration of fine particles reached 19.6 times the annual reference value established by the World Health Organization (WHO).
The Electronic Environmental Surveillance System (Selva), from the State University of Amazonas (UEA), also recorded critical air quality conditions.
At around 6 pm, sensors spread across Manaus classified the air quality as “very bad” or “very bad”. Only the equipment installed in the central region of the city registered a “moderate” level. At one of the monitored points, the index reached 218.1.
Atmosphere had little capacity to disperse pollutants, says meteorologist
Meteorologist Andrea Ramos explained that active fires in the region contribute to keeping pollution close to the surface. Normally, warming throughout the day favors the dispersion of pollutants, but this process was not sufficient this Monday.
“Throughout the day, heating normally favors some dispersion of smoke, but today this process was not enough to remove — if there was rain — or disperse/transport — when the direction and intensity of the wind makes it easier,” he declared.
And the rains?
The forecast indicates little rain in Manaus between this Monday (12) and Tuesday (13), according to the meteorologist. The possibility of showers increases on Wednesday (14) and Thursday (15), which may temporarily improve air quality.
"A more frequent rain condition appears mainly from the weekend to the beginning of next week. Until then, the air quality can still fluctuate a lot from one period to another", he pointed out.
Influence of El Niño
The meteorologist explained that El Niño could worsen conditions favorable to fires in the Amazon. In certain periods, the phenomenon reduces rainfall and increases temperatures in parts of the region, leaving vegetation drier and more susceptible to fire.
Ramos highlighted, however, that El Niño does not directly produce smoke, but can create climate conditions favorable to the occurrence and persistence of fires.
"El Niño can contribute to this scenario because, in certain periods, it favors reduced rainfall and higher temperatures over parts of the Amazon region, increasing vegetation dryness and susceptibility to fire. But it is important to highlight that El Niño does not produce smoke," he stated.
Fire outbreaks in Amazonas
The worsening of the smoke that covers the region occurs amid the increase in records of fire outbreaks in the state. In the first ten days of October this year, Amazonas recorded 1,380 fires, an increase of 271% compared to the same period in 2025, when 372 records were recorded.
The data comes from the Fire Panel, the Management and Operational Center of the Amazon Protection System (Censipam).
Of the total recorded this month, 1,186 outbreaks were identified in public areas, 93 on private properties and 101 in places where the land status was not defined. In the same period, 246 outbreaks were registered in federal settlement areas, 116 reached indigenous lands and 97 occurred in conservation units.
Smoke covers Manaus — Photo: Reproduction/Social Networks
