25 Tamil Nadu districts have received ‘largely’ excess rain so far in October
No district saw deficient or notably low rainfall during this period. The IMD report pointed to a steady and widespread rain pattern, suggesting an early and strong start to the northeast monsoon across the State.
Weekly District-wise departures
There has been a steady increase in rainfall departure over three successive weeks, as per the IMD’s weekly rainfall analysis.
In the first week (October 1–8), the State registered a 3 per cent surplus rainfall, reflecting near-normal rainfall across the majority of districts.
Rainfall was 34 per cent surplus in the second week (October 9–15), as Dharmapuri (56 per cent), Tirunelveli (99 per cent), and Vellore (180 per cent) recorded heavy rain.
In the third week (October 16–22), the rainfall surplus soared by 82 per cent, mainly due to heavy rain in Tirunelveli (199 per cent of normal), Ranipet (203 per cent), Cuddalore (133 per cent), Ramanathapuram (136 per cent), and Tiruvarur (177 per cent).
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Daywise rainfall
In the 24 hours ending at 8.30 a.m. on Thursday, Ranipet received 13 cm of rainfall, while Harur in the Dharmapuri district received 11 cm. This was followed by Mohanur in Namakkal, Vintworth Estate in the Nilgiris, and Vellakoil in Tiruppur district, each of which received 9 cm of rain.
In Chennai, Medavakkam and Ambattur recorded 4 cm of rainfall, while Pallikaranai, Maduravoyal, Uthandi, and Sholinganallur received 3 cm each.
Weekly report
During the week, Ariyalur, Chengalpattu, Chennai, Coimbatore, Cuddalore, Erode, Kallakurichi, Kancheepuram, Kanyakumari, Karur, Madurai, Mayiladuthurai, Nagapattinam, Nilgiris, Perambalur, Pudukkottai, Ramanathapuram, Ranipet, Salem, Sivaganga, Tenkasi, Thanjavur, Theni, Tirunelveli, Tirupattur, Tiruvallur, Tiruvannamalai, Tiruvarur, Thoothukudi, Tiruchirappalli, Vellore, Villupuram and Virudhunagar districts, along with Puducherry and Karaikal, recorded heavy to very heavy rainfall, the IMD said.
Dindigul, Namakkal, and Tiruppur districts recorded excess rainfall, while Dharmapuri and Krishnagiri districts experienced normal rainfall during the week.
Seasonal distribution
Between October 1 and 22, Ariyalur, Chennai, Cuddalore, Erode, Kallakurichi, Kancheepuram, Mayiladuthurai, Nagapattinam, Nilgiris, Pudukkottai, Ramanathapuram, Ranipet, Sivaganga, Tenkasi, Thanjavur, Theni, Tirunelveli, Tirupattur, Tiruvallur, Tiruvannamalai, Tiruvarur, Thoothukudi, Vellore, Villupuram, and Virudhunagar districts, along with Puducherry and Karaikal, recorded large excess rainfall.
Chengalpattu, Coimbatore, Dharmapuri, Dindigul, Karur, Krishnagiri, Madurai, Namakkal, Perambalur, Tiruppur, and Tiruchirappalli districts received excess rainfall.
Salem and Kanyakumari districts received normal rainfall.
Strong start to north east monsoon
Tamil Nadu recorded 107.6 mm of actual rainfall against a normal of 41.3 mm during the week ending October 22, a 161 per cent surplus.
For the post-monsoon season from October 1 to 22, the State received 197.7 mm of rainfall against the normal 108.5 mm, a 82 per cent surplus.
The data underscores consistent and widespread rainfall activity across both coastal and interior districts, signalling a robust monsoon season.
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Published on October 23, 2025
