Unexpected Amazon Hotspot: Central North Faces Fastest Rise in Extreme Heat

The central north Amazon — an area of dense forest, natural savannas and important Indigenous territories — was not previously seen as the region hit hardest by climate change. A new study, published in the journal Communications Earth & Environment, finds it now has the fastest growth in climate extremes anywhere in the Amazon basin.

The research, led by scientists at Lancaster University in the UK with WWF UK and an international team of more than 50 researchers, found that 10% of the Amazon basin — an area of over 700,000 square kilometers (270,000 square miles), larger than Afghanistan — has seen extreme dry-season temperatures rise by at least 0.75°C a decade, and by more than 3.22°C since 1981, over the past 43 years.

By contrast, average Amazon temperatures are rising by 0.21°C a decade, in line with average global warming, a rate at which the extremes do not show up. The team divided the Amazon into 11-kilometer (7-mile) grid cells, combining satellite and weather-station data to model temperature and a new water-deficit measure from 1981 to 2023.

Jos Barlow, a Lancaster University professor and the study's lead author, said the Southern Amazon, long hit by deforestation, remains fastest-warming by average temperature, while the central north shows the fastest rise in extremes. Since that area lies far from the deforestation frontier, he said, the change cannot be explained by local land use: "It's the world's emissions that are responsible." Dr. Nathália Carvalho, of the Lancaster Environment Centre, said the Amazon's climate "is not changing uniformly."

The 2026 El Niño, expected to be the largest in living memory, could bring extreme heat and drought just two years after the Amazon's last major drought in 2024. Studies already link these extremes to the first observed mass deaths of mammals in the Amazon, shrinking bird populations, forest fires causing air pollution in Manaus, and drying rivers harming forest-dwellers' health.