The India Meteorological Department (IMD) has predicted moderate rainfall accompanied by thunderstorms and lightning across several parts of Tamil Nadu on Saturday, October 4, 2025. The rainfall is attributed to a deep depression that has formed over the Bay of Bengal, and the Regional Meteorological Centre (RMC) has said the wet spell is likely to continue in certain regions of the state until October 8.
Tamil Nadu Weather Update
According to the IMD, “Moderate rain with thunderstorm and lightning is very likely at isolated places over Ariyalur, Chengalpattu, Chennai, Cuddalore, Dharmapuri, Kallakurichi, Kanchipuram, Krishnagiri, Ranipet, Salem, Thiruvallur, Tirupathur, Tiruvannamalai, Vellore, Viluppuram, Delta districts and Puducherry-Karaikal.”
Rainfall is also expected in isolated pockets of Dharmapuri, Dindigul, Erode, Krishnagiri, Karur, Namakkal, Pudukkottai, Sivaganga, Trichy, Salem, Tiruvannamalai, Tirupattur and Vellore districts.
Heavy rains triggered flash floods at the Meghamalai waterfalls in the Western Ghats, prompting officials to prohibit public entry into the tourist spot.
#WATCH | Dindigul, Tamil Nadu: Rain lashes parts of the city pic.twitter.com/Cqesn38E5y
— ANI (@ANI) October 4, 2025
The IMD has also warned that maximum temperatures are likely to remain 2–3°C above normal in some parts of Tamil Nadu on October 3, and continue to stay higher than usual at isolated locations between October 4 and October 7.
Southwest Monsoon Ends, Northeast Monsoon Looms
The southwest monsoon officially ended in Tamil Nadu recently, with the state recording an average of 325.5 mm of rainfall between June and September. Chennai logged a 29% surplus in rainfall during this period.
With the southwest monsoon’s withdrawal, early signs of the northeast monsoon have begun to appear. Though it may take more time for an official onset, the depression over the Bay of Bengal is already bringing rain across the state.
Independent weather blogger Pradeep John, known as Tamil Nadu Weatherman, noted that the conditions are favorable for thunderstorms across many districts for the next two days. He predicted that Chennai and its neighboring districts of Kancheepuram, Tiruvallur and Chengalpattu (KTC) would wake up to rainy mornings, while widespread rains are likely in Krishnagiri, Dharmapuri, Salem, Villupuram, Tirupattur and Tiruvannamalai.
