Heavy rains likely in many districts of Tamil Nadu including Chennai on Oct. 18

Heavy rains are expected to occur on Sunday (October 18, 2026) too in districts including Chennai, Kancheepuram, Chengalpet, Salem, Krishnagiri, Tiruchi, Ariyalur, Nilgiris, Dharmapuri, Tiruvallur, Cuddalore, Tiruvannamalai, Erode and Puducherry, according to the Regional Meteorological Department.

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

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

In the period from 6 p.m. on October 17, 2026 to 6 a.m. on October 18, 2026, several parts of Chennai witnessed heavy rainfall including Meenambakkam (28.5 cm), Chennai Central (27.4 cm), Ennore (21.5 cm) and Tiruvottiyur (22.4 cm).

With regard 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 occurs within 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 rapid surface runoff, waterlogging and urban flooding. Based on the prevailing meteorological conditions and the observed rainfall pattern associated with the cyclonic circulation, the rainfall over Chennai and its neighbourhod appears to have resulted from organised, widespread convective activity associated with the cyclonic circulation, rather than an isolated, highly localised cloudburst event.”