Chennai: The Chennai Meteorological Department has issued an extensive heavy rainfall warning for a majority of districts in Tamil Nadu, forecasting a week-long spell of intense weather activity starting today, October 13, 2025. The alert comes as a low-pressure area consolidates over the southwest Bay of Bengal and the adjacent south Tamil Nadu coast, promising widespread precipitation across the state and the union territories of Puducherry and Karaikal.
The weather office has predicted light to moderate rain with thunder and lightning at many places across the region throughout the week, with specific districts being flagged for isolated to widespread heavy rainfall on different days.
Tamil Nadu Weather Forecast This Week
The initial phase of the weather system on October 13 is expected to bring heavy rain to one or two places in the hilly areas of Coimbatore and Tiruppur districts. The Nilgiris, Erode, Theni, Madurai, Dindigul, Virudhunagar, Dharmapuri, Salem, Namakkal and Tenkasi districts have also been put on alert for heavy downpours.
By October 14, the pattern is expected to consolidate, with heavy rainfall likely in the hilly areas of Coimbatore district, alongside the Nilgiris, Theni and Tenkasi districts.
A significant intensification and southward shift of the rainfall is forecast from Wednesday, October 15. On this day, heavy rain is likely to occur at many places in the hilly areas of Tirunelveli district. The coastal and southern districts of Thoothukudi, Ramanathapuram, Virudhunagar, Sivaganga, Pudukottai, Nagapattinam, Mayiladuthurai, Thanjavur, Tiruvarur and the Karaikal area are also expected to experience widespread heavy rainfall.
The following day, October 16, will see the heavy rain pattern spread again. Heavy rain is likely at one or two places in the hilly areas of Coimbatore and Tirunelveli districts, as well as in Kanyakumari, Thoothukudi, Tenkasi, Virudhunagar, Madurai, Ramanathapuram, Sivaganga, Nilgiris, Theni and Dindigul districts.
Tamil Nadu Rain Alert: Widespread Heavy Rain Alert for Southern and Coastal Districts
The forecast for the weekend indicates the most widespread weather activity. On October 17, heavy rainfall is likely at many places in Kanyakumari, Tirunelveli, Thoothukudi, Tenkasi, Virudhunagar, Madurai, Ramanathapuram, Sivaganga, Pudukkottai, Nagapattinam, Mayiladuthurai, Thanjavur, Thiruvarur districts and the Karaikal area.
The alert expands further on October 18, with heavy rain expected at many places in Kanyakumari, Tirunelveli, Thoothukudi, Tenkasi, Virudhunagar, Madurai, Ramanathapuram, Sivaganga, Pudukkottai, Nagapattinam, Mayiladuthurai, Thanjavur, Thiruvarur, Cuddalore, Theni, Dindigul districts and the Karaikal area.
weather blogger Pradeep Jhon, widely known as the ‘Tamil Nadu Weatherman,’ has forecast that intense rainfall activity is set to expand and intensify across the state, with South Tamil Nadu joining the “rain party” starting today.
His prediction aligns with the multi-day heavy rain alert issued by the Chennai Meteorological Department, providing a more granular outlook for the days ahead.
Tamil Nadu Weatherman Predictions
In his latest analysis, Pradeep Jhon stated, “Another rocking day ahead for Interior Tamil Nadu, but this time South TN joins the party.” He specifically identified districts including Kanyakumari, Tenkasi, Theni, Tirunelveli, Virudhunagar, and interior Thoothukudi as areas poised to receive their share of good rains. This prediction dovetails with the official warning for these districts, which are on alert for heavy rain from October 13th through the weekend.
Commenting on the weather pattern for coastal areas, including the capital city, he described the current conditions as a “trademark transition season pattern.” He noted that for the Chennai region, also known as KTCC, the same story continues with sudden and surprise showers popping up out of nowhere in a few spots. This indicates the unstable atmospheric conditions prevailing as the season shifts.
Northeast Monsoon’s Grand Entry of Widespread Rains from Mid-Week
The most significant part of the blogger’s forecast points to a major shift around mid-week. “But get ready, KTCC,” he advised, “From October 15/16th onwards, the easterlies will start to take charge, and widespread rains will make a grand entry with the onset of the monsoon.” This timeline corroborates the Chennai MET Department’s alert, which predicts a significant intensification and a southward shift of rainfall from October 15th, with heavy rain likely at many places across southern and coastal districts.