Northeast monsoon arrives early over Tamil Nadu; heavy rains lash many districts

The Northeast monsoon, which brings a serious share of Tamil Nadu’s annual rainfall, arrived on Thursday (October 16, 2025), marking an early onset forward of its traditional arrival date of October 20.

The Regional Meteorological Centre (RMC), Chennai, declared the simultaneous exit of the Southwest monsoon from the nation and the onset of the Northeast monsoon rainfall over elements of the southern peninsular area, together with Tamil Nadu, Puducherry, and Karaikal, on Thursday.

The higher air cyclonic circulation prevailing over Comorin space, which introduced pretty widespread rainfall over many elements of the State, together with the setting in of easterly winds, have been cited as key indicators for the arrival of the Northeast monsoon.

It might be recalled that Tamil Nadu additionally witnessed an early onset of the Northeast monsoon final 12 months, on October 15. The monsoon signed off on a optimistic observe with 33% extra rainfall.

This 12 months, the monsoon’s first spell introduced intense downpours in lots of locations. Within the 24 hours ending 8.30 a.m. on Thursday, Kayalpattinam and Thoothukudi acquired very heavy rainfall of 15 cm every, adopted by Thiruchendur with 13 cm. A number of different locations, together with Ranipet, Tirunelveli, and Mayiladuthurai additionally reported heavy rainfall. Average showers lashed many locations in and round Chennai.

The RMC has issued an orange alert for Theni, Tenkasi, Tirunelveli, and Ramanathapuram districts, warning of remoted very heavy rainfall on Thursday. It has additionally forecast heavy rain in 22 different districts, together with Chennai, Madurai, and Erode.

In the meantime, the Water Assets Division has elevated water launch from the Poondi reservoir in Tiruvallur district to 4,500 cubic ft per second on Thursday attributable to heavy inflows. The water degree within the reservoir, one of many Chennai’s key ingesting water sources, is rising steadily. Officers mentioned a portion of water launched into Kosasthalaiyar river is diverted to Cholavaram tank for storage, whereas the remainder is channelled to checkdams downstream throughout the river.