Mumbai and its suburbs have been lashed by incessant rainfall for four consecutive days, with the India Meteorological Department (IMD) predicting continued heavy rainfall over the next 24 hours, followed by a period of moderate precipitation. The deluge, beginning around August 16, has already brought over 800 mm of rainfall—well above the city’s monthly average of 560.8 mm—raising alarm over the increasing frequency of extreme weather events.



Monsoon Systems Converge, Amplifying Rainfall
The intense rainfall has been attributed to the convergence of multiple weather systems that have collectively intensified the monsoon surge over coastal Maharashtra. The monsoon trough currently stretches from Diu to the Central East Bay of Bengal via Surat, Nandurbar, Amravati, and South Odisha.

“Vigorous monsoon conditions have developed due to a low-pressure area over Vidarbha, a cyclonic circulation over the Northeast Arabian Sea and Southeast Gujarat, and a depression over the Bay of Bengal. An active offshore monsoon trough from Konkan to North Kerala has further intensified the system,” explained Mahesh Palawat, a meteorologist at Skymet Weather.

Climate Change: An Underlying Catalyst
While extreme rainfall events are not new to Mumbai, experts assert that climate change is acting as a catalyst, amplifying their intensity and frequency.

“Climate change acts like a steroid,” said Dr. Raghu Murtugudde, a climate scientist and emeritus professor at the University of Maryland. “The warming over the Middle East and the Arabian Sea has enhanced the moisture content in the monsoon winds, pushing moisture northward into the Western Ghats.”

He referenced a 2023 study titled “Middle East Warming in Spring Enhances Summer Rainfall over Pakistan”, which found that land heating in the Middle East accounted for 46% of the intensified rainfall over Northwest India and Pakistan from 1979 to 2022.

Dr. Akshay Deoras, a research scientist at the National Centre for Atmospheric Science, University of Reading, added, “Mumbai’s current downpour is a classic case of climate-induced intensification. While July was the driest in a decade, we are now witnessing intense rainfall over shorter durations—exactly what is expected in a warming climate.”

Adaptation, Not Just Forecasting, Is Key
Experts unanimously emphasize that early warning systems alone are insufficient without accompanying urban planning and resilience measures.

“The only way forward is through robust, citizen-centric early warning and nowcast systems,” said Dr. Subimal Ghosh, the institute chair professor at IIT Bombay. He referred to the Mumbai Flood Monitoring System developed by IIT Bombay, which is already helping disseminate critical information to stakeholders.

However, forecasting must be complemented by better coordination. K.G. Ramesh, former director general of the Indian Meteorology Department (IMD), stated, “If alerts are not communicated in time, their purpose is defeated. We need clearly defined evacuation plans and must identify high-risk zones well in advance.”

Dr. Vishwas Chitale, fellow at the Council on Energy, Environment and Water (CEEW), called for a multi-pronged strategy that includes:

* Mapping of flood-prone areas
* Upgradation of drainage infrastructure
* Increasing urban green cover
* Use of Intensity-Duration-Frequency (IDF) curves to model future rainfall scenarios and water discharge rates

CEEW has already developed a Thane City Action Plan for Flood Risk Management (2024), which provides a robust framework using over five decades of rainfall data. The plan includes ward-wise urban flood risk indices, peak discharge estimates, and actionable short-, medium-, and long-term strategies.

Building Resilience for the Future
Urban flooding remains India’s most frequent and damaging natural disaster. Abinash Mohanty, global sector head, Climate Change and Sustainability at IPE Global, emphasized, “Floods rank highest in terms of frequency and damage. Mumbai’s 12 million residents are now accustomed to submerged vehicles and knee-deep water. But we must not normalize this. IPE Global is currently supporting BMC in developing a real-time, AI-ML enabled Multi-Hazard Risk Atlas for Mumbai to help climate-proof the city.”