Tamil Nadu வானிலை Alert 18 Sep 2026: Heavy Rain Districts & IMD Forecast

IMD heavy rain warning for Tamil Nadu on 18 September 2026

வானிலை updates from 18 September 2026 show the Chennai weather centre issuing a heavy rain alert for Tamil Nadu. On that day the warning covered six districts for the current day and expanded to eleven districts for 19 September, driven by an atmospheric circulation over north Tamil Nadu and a low-pressure corridor extending towards the southeast Arabian Sea.

Districts under heavy rain alert

According to Polimer News reporting on 18 Sep 2026 14:22 IST, the six districts flagged for heavy rain on 18 September were Nilgiris, Coimbatore, Tiruvannamalai, Dharmapuri, Krishnagiri and Kallakurichi. The same bulletin notes a next-day alert.

Hindu Tamil Thisai’s 18 Sep 2026 update from the Chennai weather centre lists the 19 September heavy rain possibility for Nilgiris, Coimbatore, Krishnagiri, Dharmapuri, Ranipettai, Viluppuram, Tiruvannamalai, Tirupathur, Vellore, Kallakurichi and Madurai, with isolated thunder, lightning and strong winds expected.

Atmospheric setup behind the forecast

The alert cites an atmospheric circulation over the interior and adjoining parts of north Tamil Nadu at about 4.5 km height, and a low-pressure trough from Marathwada to the southeast Arabian Sea through interior Karnataka and Kerala at about 5.8 km height. The configuration is expected to bring thunder-storm activity and heavy showers to the warned districts.

Recent rainfall recorded

As per the 8:30 am observation for 18 September, the highest 24-hour totals reported by the weather centre were Tiruchirappalli district Pullampadi 8 cm, and Nilgiris Kodanadu, Tiruchirappalli Kallakkudi, Malavai, Thanjavur Kallanai and Ariyalur Melakkaruppur each 7 cm. These totals underline the intensity of the current system.

What residents should do

• Avoid non-essential travel in the listed districts, especially in low-lying and landslide-prone areas of Nilgiris and Coimbatore.
• Secure loose outdoor items and keep drainage around homes clear.
• Monitor updates from the IMD and local media. Reports from Polimer News, Hindu Tamil Thisai and Thanthi TV carried the 18 September bulletins.
• Other west-ridge districts including Chennai, Kanchipuram, Chengalpattu and Tiruvallur were forecast for moderate to light rain on 19 September, with isolated thunderstorms in the evening.

The warning remains valid until the system dissipates. The exact cessation date was not confirmed in the 18 September bulletins.