Heavy rain likely in many districts of Tamil Nadu including Chennai on October 18

Heavy northeast monsoon rain lashed several parts of Chennai overnight, leaving roads waterlogged and disrupting normal life. | Photo credit: Johan Sathyadas J.

Heavy rains are also expected on Sunday (October 18, 2026) in districts including Chennai, Kancheepuram, Chengalpet, Salem, Krishnagiri, Tiruchi, Ariyalur, Nilgiris, Dharmapuri, Tiruvallur, Cuddalore, according to Tiruvannae or Puchercherry regional division.

According to the department, there is significant convective cloud development over the north coast of Tamil Nadu and adjoining sea areas associated with cyclonic circulation over the region, which is likely to bring heavy to very heavy rainfall to and around Chennai on 18 October as well.

The Meteorological Department said the heavy to very heavy rainfall that Chennai experienced on October 17. Parrys in Chennai recorded a maximum of 36 cm of rainfall in the downpour that occurred late on Saturday (17 October 2026) and early on Sunday (18 October 2026). It was followed by Kathivakkam, which received 34.4 cm of rainfall, according to the Greater Chennai Corporation’s Integrated Command and Control Centre.

Between 6:00 PM on 17 October 2026 and 6:00 AM on 18 October 2026, several parts of Chennai witnessed heavy rains, including Meenambakkam (28.5 cm), Chennai Central (27.4 cm), Ennore (21.5 cm) and Tiruvottiyur (22.4 cm).

Referring to the heavy downpour over Chennai during this period, the Meteorological Department said: “In India, a cloudburst is conventionally described as an event in which 100 mm or more of rainfall falls in one hour over a small area, typically around 20-30 square kilometres. Such intense rainfall is generally associated with deep convective clouds and can lead to meteorological and rapid surface runoff. Rainfall associated with cyclonic circulation, the rainfall over Chennai and its vicinity appears to have been the result of organized, widespread convective activity associated with the cyclonic circulation, rather than an isolated, highly localized cloudburst event.

On Sunday (October 18, 2026) afternoon, mobile alerts were received: “As Chennai will witness very heavy rains, people are requested to be cautious. Please follow the official weather reports.” The report was sent by the Tamil Nadu State Disaster Management Authority (TNSDMA).

Published – 18 Oct 2026 12:04 IST