Unseasonal February rainfall likely over some parts of south Tamil Nadu this week

A trough over the equatorial Indian Ocean and the adjoining southwest Bay of Bengal is likely to influence a wet spell in parts of Tamil Nadu till February 26. In back-to-back weather developments this month, the Regional Meteorological Centre (RMC) has forecast prospects of isolated heavy rain in southern districts over the weekend. The RMC has forecast some parts of Chennai may also receive light or moderate rain on Saturday (February 21, 2026).

While southern districts are expected to get rain at many places on February 21 and 22, there is a possibility of light to moderate rain in a few places over north Tamil Nadu. Thunderstorms may occur in some parts with gusty winds reaching speeds of 30-40 kmph over the State. RMC officials said the prevailing foggy weather could ease over the next few days. The trough extends up to the Lakshadweep area across south Tamil Nadu and south Kerala and is likely to bring scattered rain to Tamil Nadu.

While six districts, including Tirunelveli, Thoothukudi, and Kanniyakumari, have chances of isolated heavy rain on Saturday, parts of Dindigul, Madurai, and Theni districts may be covered by intense rain on Sunday.

V.R. Durai, Director, Area Cyclone Warning Centre, RMC, said the weather system over the equatorial Indian Ocean and the southwest Bay of Bengal would trigger unseasonal rainfall over south Tamil Nadu. The system is transporting moisture inland and is likely to bring a wet spell. Moreover, warmer than normal sea surface temperatures over the equatorial Indian Ocean have enhanced moisture supply and atmospheric instability, resulting in rain that is unusual for February, which is typically a dry month in the region, he said.

While the previous weather system, which prevailed over the sea and did not bring significant rain to the State, is expected to move towards Sri Lanka by Saturday, the RMC is also monitoring a fresh low-pressure area developing over the equatorial Indian Ocean and the southeast Bay of Bengal.

B. Amudha, Head, RMC, said such formation of weather systems over the Bay of Bengal is not frequent based on years of monitoring. With the earlier weather system weakening, a cyclonic circulation is being watched for its potential to develop into a low-pressure area and its impact over Tamil Nadu. More clarity on its impact is expected in two days, depending on its movement.

The State remained largely dry on Friday with none of the weather stations recording rain till 6 p.m. Tamil Nadu has received a surplus rainfall of 33.8 mm against its seasonal average of 21.5 mm since January 1. The RMC has forecast some parts of Chennai may also receive light to moderate rain on Saturday.