IMD Forecasts Below-Normal September Rain for Chennai Amid Monsoon Flood Concerns

The India Meteorological Department (IMD) has forecast below-normal rainfall across the country for September, with projections indicating that Chennai and neighbouring Tiruvallur district are also likely to receive below-normal precipitation during the month.

While the projection suggests a relatively dry period ahead of the northeast monsoon, meteorologists and disaster-management experts warned that monthly rainfall figures do not eliminate the risk of urban flooding. A city can record below-average rainfall across a month and still face severe inundation if heavy volumes of water fall within a short window of a few hours.

Past weather events in Chennai have demonstrated that sudden, intense spells can quickly overwhelm local stormwater networks, flood low-lying neighbourhoods, and disrupt transport and essential services. Experts noted that flood risks are driven primarily by the concentration and intensity of individual rain events rather than overall seasonal averages.

Ahead of the northeast monsoon, the Greater Chennai Corporation (GCC) has continued preparatory work across the city. Civic operations currently underway include stormwater drain construction, desilting of existing channels, and the setup of emergency-response arrangements.

Civic readiness will depend on whether key drainage links are connected, whether canals and waterways maintain sufficient carrying capacity, and whether drains remain clear of blockages when the first heavy spells hit the city.