Dhaka, June 2 -- Silchar, the second-biggest city in India's northeastern state of Assam, has recorded its highest single-day rainfall in 132 years on the first day of June, with 415.8 millimetres falling in just 24 hours.

The highest previous rainfall record of 290.3 mm was set in 1893.

The torrential downpour left most of Silchar, 116 kilometres east of Sylhet, submerged, causing widespread flooding.

According to the India Meteorological Department (IMD), the extreme weather was triggered by a combination of upper-air cyclonic circulation and a lower-level trough, creating unstable atmospheric conditions.

A particularly intense weather zone stretching from central Assam to Arunachal Pradesh has been linked to a trough extending from...