Science & Tech · Science & Environment · 1 hr ago
Amazon fires and a strong El Niño threaten regional rainfall
Amazonas recorded 1,380 fire hotspots from October 1 to 10, up from 372 in the same period in 2025.
The fires have affected areas across the state, and smoke led to school closures in Manaus.
The concern extends beyond the region because the Amazon forest releases water vapor that helps bring rain to Brazil’s Center-West, Southeast and South, as well as the Plata basin.
The World Meteorological Organization forecasts a potentially record-strength El Niño, which can bring hotter and drier conditions to parts of the Amazon.
Dryer vegetation can help human-started fires spread, while fires and deforestation together can reduce the forest’s release of moisture.
A study of 1980 to 2019 found that rainfall fell by 8% to 11% in the southern Amazon basin, with deforestation mainly accounting for 52% to 72% of that decline.
The effects of the current fires on rainfall beyond the Amazon are not yet known, and how long or widespread drought will be in 2027 also depends on the Atlantic and atmospheric conditions.
Amazonas recorded 1,380 fire hotspots from October 1 to 10, a 271% increase from the same period in 2025.
The fires coincide with an El Niño that the World Meteorological Organization says could reach record intensity.
El Niño can bring hotter and drier conditions to parts of the Amazon, helping fires spread through vegetation with less moisture.
Fires and deforestation reduce the forest’s release of water vapor, which helps supply rainfall across parts of Brazil and the La Plata basin.
The article says the rainfall effect of the current fires outside the Amazon cannot yet be quantified.
- Who
- Fires are affecting the Brazilian state of Amazonas. The World Meteorological Organization forecasts a strong El Niño.
- What
- Fires and El Niño threaten the Amazon forest’s role in recycling moisture and supporting regional rainfall.
- When
- Fires were reported in September and October 2026. The El Niño peak is expected in December.
- Where
- Amazonas, Brazil, and the Pacific’s Niño 3.4 region. The rainfall impacts could extend to central-western, southeastern and southern Brazil and the La Plata basin.
- Why
- El Niño can favor hotter, drier conditions in parts of the Amazon, while fire and deforestation reduce evapotranspiration.
This story does not have two clearly opposing sides.
Fires began at Lago do Canaçari and remained active for weeks.
INPE recorded 3,726 fire hotspots in Amazonas, compared with 942 in 2025 and 6,879 in 2024.
Amazonas recorded 1,380 fire hotspots, compared with 372 in the same period of 2025.
The World Meteorological Organization forecasts a mean Niño 3.4 temperature anomaly of 3.7°C.
The El Niño is expected to peak.
The forecast gives a probability close to 100% that El Niño conditions will persist through this month.
- Amazonas hotspots, October 1–10
- 1,380
- Increase from same period in 2025
- 271%
- INPE hotspots, September 2026
- 3,726
- Forecast Niño 3.4 anomaly, October–December
- 3.7°C
- Rainfall decline in southern Amazon basin, 1980–2019
- 8%–11%
What people are saying
The risk is not the disappearance of the winds; it is the progressive loss of the moisture they carry and the rain that this moisture helps form.
Sources
Related news
Political identity shapes trust in science in Brazil, columnist argues
International timekeepers set to vote on ending leap seconds
Researchers try to restore California kelp forests by reintroducing sunflower sea stars
Mining pressures protected areas as wildlife populations decline in Africa
Maynooth Researchers Build a DNA Computer That Needs No Continuous Power
Cape Town plans to relocate two baboon troops from Simon’s Town
Ringed barn owls will help assess wildlife-friendly farming
Super El Niño strengthens to unprecedented levels, with impacts expected into 2027
Study Finds Stem-Cell Embryo Models Do Not Fully Match Human Embryos
Researchers create fertile female clones from male mice
Jonathan the tortoise’s genes may offer clues to healthy aging
