Why do Bangladesh’s rivers often flood between June and October?

Bangladesh’s rivers frequently overflow their banks between June and October primarily due to the monsoon climate. During this period, the region experiences heavy rainfall brought by the southwest monsoon, which typically lasts from June through September or early October.123

This intense seasonal precipitation is further amplified by the massive discharge from major river systems—such as the Ganges, Brahmaputra, and Meghna—which carry enormous volumes of water from rain-soaked regions outside the country's borders, including the Himalayas. While these annual inundations are essential for replenishing fertile silt deposits, they also regularly cause significant flooding that can damage crops and impact local populations.14