Bangladesh is likely to experience a weaker and drier monsoon along with a fresh spell of heatwaves this year, as unusually warm Pacific Ocean temperatures signal the development of an El Niño event, meteorologists and climate experts say.
The phenomenon, marked by rising sea surface temperatures in the tropical Pacific, disrupts normal weather patterns and reduces rainfall in parts of South Asia.
Leading meteorological agencies in the United Kingdom and the United States say a significant shift is underway in the tropical Pacific, with clear signs that El Niño is developing and is expected to peak around September.
Experts say the phenomenon shifts cloud formation toward the central Pacific, reducing moisture flow to the region. This could leave Bangladesh under high-pressure systems, limiting rainfall and weakening the monsoon’s cooling effect.
“Normal supply of moisture from the sea is disrupted due to El Niño,” Md Marufur Rahman, assistant professor at the Department of Disaster Science and Climate Resilience at the University of Dhaka, told Dhaka Tribune.
“As a result, Bangladesh may experience low rainfall, prolonged dry spells, or even drought,” he added.
Dr Md. Rabiul Awal, chairman of the Department of Meteorology at the University of Dhaka, said if El Niño develops before the monsoon season, it could significantly weaken rainfall.
“Weak means there will be much less rainfall than usual, which will have some consequences,” he said.
Bangladesh saw severe impacts during the 2023–2024 El Niño, when prolonged heatwaves pushed temperatures between 40°C and over 43°C across 51 of 64 districts, according to the Bangladesh Meteorological Department (BMD).
The UK Met Office said clear signs point to an emerging El Niño in the tropical Pacific. While the term “super El Niño” is not officially recognized, climate communicator Grahame Madge said it could be among the strongest events this century, comparable to 1998.
The US National Centers for Environmental Prediction (NCEP) under NOAA estimates a 61% chance of El Niño forming and persisting through at least the end of 2026.
A 2020 study published by Springer Nature found that the El Niño–Southern Oscillation (ENSO) strongly influences Bangladesh’s rainfall and temperature, with potential long-term variability in monsoon patterns.
El Niño, part of the ENSO cycle, occurs when weakened trade winds allow warm Pacific waters to shift eastward, disrupting global climate systems.
Globally, the phenomenon is expected to bring hotter, drier conditions to Australia and Indonesia, raising wildfire risks. Southern Europe may see wetter weather, while northern Europe turns colder and drier.
In the United States, eastern regions may become drier, while southern areas face heavy rain and flooding. India and southern Africa often see weaker monsoons, while East Africa may receive above-average rainfall. Southern South America tends to get wetter, while the Amazon faces drying trends that could affect its ability to absorb carbon.
