With a 187 km coastline, Nagapattinam is spread across an area of 2716 sq km. Rice takes a big share of the area under cultivation, followed by black gram, green gram, sugarcane and groundnuts. 14 out of 17 river systems in Tamil Nadu flow through the plains of Nagpattinam and drain into the Bay of Bengal. Nagapattinam receives 60% of its rainfall during the north east monsoon and 40% during the south west monsoon.