Deep depression over Bay of Bengal: Heavy rain lashes Tamil Nadu, schools shut in Dindigul, Coimbatore, Nilgiris and Theni

Tamil Nadu received moderate to heavy rainfall across several districts in the period ending 5.30 a.m. on Monday, with the Regional Meteorological Centre (RMC) recording the highest of 11.4 cm at Pamban, even as a weather system over the Bay of Bengal intensified into a deep depression.

According to the RMC, the Coimbatore weather station recorded 8 cm of rain, while HRS Vijayanagaram in the Nilgiris and Palani recorded 7 cm each. Vedasandur in Dindigul district received 6 cm. Rainfall was also reported from Tiruvallur, Nagapattinam, Thoothukudi, Tiruchi, Madurai and Kanniyakumari districts, among others.

The India Meteorological Department (IMD), in its latest bulletin, said the depression over the Bay of Bengal had moved southwestwards during the past six hours and intensified into a deep depression. The system is likely to cross the Andhra Pradesh coast between Bapatla and Visakhapatnam as a very severe cyclonic storm, with maximum wind speeds of 115-125 kmph, the bulletin said.

Under the IMD's classification, a deep depression is a low-pressure system with wind speeds of 50-61 kmph, one step below a cyclonic storm. A very severe cyclonic storm carries wind speeds of 118-166 kmph. Systems forming over the Bay of Bengal during this period often lead the weather agency to issue advisories for coastal districts and for fishermen venturing into the sea.

Schools closed

Dindigul District Collector Durga Moorthy announced that schools in the district would remain closed on Monday (October 26, 2026) because of the rain. Coimbatore District Collector Pawankumar issued a similar announcement for schools in Coimbatore district.

In the Nilgiris, District Collector Lakshmi Bhavya Tanneeru announced that all schools in Udhagamandalam, Coonoor, Kotagiri and Kundah taluks would remain closed owing to the rain. Theni District Collector Sivakrishnamurthy said schools would be closed in the Periyakulam block.

District collectors routinely order the closure of schools during spells of heavy rain as a precautionary measure. Because such orders can apply to an entire district, a single taluk or a specific block, parents and students may check with the concerned school or the district administration for confirmation before setting out.

Heavy rain is common in Tamil Nadu between October and December, when the northeast monsoon sets in. The season accounts for a large share of the state's annual rainfall and frequently brings widespread showers along with cyclonic systems that form over the Bay of Bengal and move towards the eastern coast.

Rainfall figures issued by the RMC are recorded at weather stations and expressed in centimetres, with one centimetre of rain equal to 10 mm. District-level totals can vary widely from station to station within the same spell.