Thick smoke from wildfires shrouded Autazes in Brazil's Amazonas state on October 13. Some 1,679 fires burned in the state in the first two weeks of October, up 253% from the same period in 2025, data from the country's Amazon surveillance system shows. 

A dry spell caused by El Niño, climate change and human activity raise fire risks and threaten biodiversity and public health, said Carlos Durigan, geographer and researcher at Amazon Environmental Research Institute.