Tamil Nadu Northeast Monsoon 2026: Heavy Rain Alert for Chennai and Several Districts

Widespread light rain was recorded across Chennai and its surrounding suburbs on Wednesday ahead of the expected onset of the Northeast Monsoon over the southern peninsula on Thursday, October 15, 2026. The Regional Meteorological Centre (RMC) has forecast heavy to very heavy rainfall in isolated places across Tamil Nadu.

Heavy Rainfall Alert for Tamil Nadu

According to the RMC, isolated heavy to very heavy rainfall is likely in the Nilgiris, Coimbatore, Theni and Virudhunagar districts on Thursday. Heavy rainfall is also expected in Mayiladuthurai, Nagapattinam, Tiruvarur, Thanjavur, Cuddalore, Tenkasi, Kanniyakumari, Kallakurichi, Salem, Tiruchy, Kancheepuram, Chengalpattu, Ranipet, Tiruppur and Dindigul districts, along with Puducherry and Karaikal.

Chennai is likely to receive moderate rainfall accompanied by thunderstorms and lightning in some areas.

Rain Forecast Until October 20

The weather department has forecast widespread rainfall across Tamil Nadu, with isolated heavy rain, thunderstorms, lightning and gusty winds reaching speeds of 40–50 kmph in several districts until October 20.

On Friday, October 16, heavy rain is likely in several districts, including Chennai, Tiruvallur, Kancheepuram, Chengalpattu, the Nilgiris, Coimbatore, Erode, Tiruppur, Dindigul, Theni, Salem, Dharmapuri, Krishnagiri, Tiruvannamalai, Villuppuram, Cuddalore, Mayiladuthurai, Nagapattinam, Tiruvarur and Thanjavur, along with Puducherry and Karaikal.

On October 17, isolated heavy rainfall accompanied by thunderstorms, lightning and gusty winds is expected in the Nilgiris, Coimbatore, Theni, Dindigul, Madurai, Tiruppur, Erode, Dharmapuri, Krishnagiri and several northern and coastal districts.

On October 18, heavy rainfall is likely to continue in the Nilgiris, Coimbatore, Mayiladuthurai, Thanjavur, Tiruvarur and Nagapattinam districts.

Weather System Behind the Rainfall

The RMC reported that an upper-air cyclonic circulation over the Comorin area, near the southern Tamil Nadu coast, extends up to 1.5 km above mean sea level. An easterly trough extending from this circulation towards the Northwest Bay of Bengal off the Odisha coast is also contributing to the prevailing weather conditions.

Residents are advised to follow official weather updates, exercise caution during thunderstorms and lightning, and avoid exposed areas during strong winds.