Chennai and 16 other districts of Tamil Nadu are bracing for heavy rainfall on Sunday, 19 October 2025, as persistent showers have already left low-lying neighbourhoods in the state capital waterlogged and triggered the deployment of a National Disaster Response Force (NDRF) team as a precautionary measure. The India Meteorological Department (IMD) has attributed the wet spell to an atmospheric circulation over northern Tamil Nadu and adjoining southern coastal Andhra Pradesh.

Districts Under Heavy Rain Alert

Besides Chennai, the districts forecast to receive heavy rain on Sunday include Tiruvallur, Kancheepuram, Chengalpattu, the Nilgiris, Coimbatore, Dharmapuri, Krishnagiri, Salem, Villupuram, Kallakurichi, Cuddalore, Ariyalur, Tiruchirappalli, Perambalur, Tiruvannamalai, and Erode. The weather system is expected to bring rain to several northern, western, and central parts of the state.

Water has accumulated in low-lying areas of Chennai, raising concerns over further inundation if rainfall continues through the day. Authorities have initiated precautionary arrangements to enable an emergency response should conditions deteriorate.

NDRF Team Sent to Chennai

Following heavy rain recorded at six locations in Chennai on Saturday, an NDRF team is being dispatched to the city. The personnel will be drawn from the force's battalion stationed at Nagarikuppam, near Arakkonam. The deployment is intended to strengthen rescue preparedness in the event of flooding — not a response to an active emergency, officials indicated.

This comes amid a pattern seen in recent years where pre-monsoon and northeast monsoon cycles bring intense spells to Tamil Nadu's coast, often overwhelming urban drainage in Chennai within hours of sustained rainfall.

Monday Forecast Widens the Alert Zone

The IMD has also forecast heavy rain across a broader swath of Tamil Nadu on Monday, 20 October 2025. Districts covered include Chennai, Chengalpattu, Tiruvallur, Kancheepuram, Villupuram, Cuddalore, Mayiladuthurai, Nagapattinam, Thanjavur, Tiruvarur, Pudukkottai, Ramanathapuram, Sivaganga, Thoothukudi, Kallakurichi, Ariyalur, and Perambalur.

Heavy rain accompanied by thunderstorms and lightning is additionally forecast for Tiruchirappalli, the Nilgiris, Coimbatore, and Tirunelveli on Monday, according to the department. The two-day outlook indicates that both the Cauvery delta districts and parts of southern Tamil Nadu could be affected alongside the already-impacted northern districts.

What Residents and Authorities Are Watching

Chennai and its neighbouring districts appear in the heavy rain forecasts for both Sunday and Monday, making the next 48 hours critical for civic agencies managing drainage and flood relief. The NDRF team's presence is intended to cut response time if waterlogging escalates to flooding in vulnerable pockets of the city.

Notably, Chennai has faced repeated inundation events during the northeast monsoon season, with the 2015 floods serving as the benchmark catastrophe that continues to shape the city's flood preparedness framework. With the atmospheric circulation system yet to weaken, authorities are expected to keep relief teams on standby through at least Monday.