IMD issues heavy rain alert for 5 Tamil Nadu districts as southwest monsoon arrives
Synopsis
The IMD has declared the southwest monsoon's onset and placed five Tamil Nadu districts — including Madurai, Coimbatore and the Nilgiris — on heavy rain alert, with a Bay of Bengal low-pressure system set to sustain showers for at least three more days. Fishermen have been warned off multiple sea zones as winds build to 60 kmph along the southern coast.
Key Takeaways
The IMD has declared the official onset of the southwest monsoon and issued a heavy rain alert for Tamil Nadu .
Theni, Dindigul, Madurai, Coimbatore and the Nilgiris are forecast to receive heavy rainfall on Sunday and Monday .
Karur, Tiruchy and Sivaganga are also on alert for heavy showers on Monday .
A low-pressure area over the southwest Bay of Bengal is expected to sustain rainfall for at least three more days .
Gusty winds up to 40 kmph and thunderstorms with lightning are likely at isolated locations.
Fishermen have been warned against venturing into the Gulf of Mannar , Kanyakumari Sea , and parts of the south Bay of Bengal , where winds may reach 60 kmph .
The India Meteorological Department (IMD) has announced the official onset of the southwest monsoon, with the Regional Meteorological Centre (RMC) in Chennai forecasting heavy rainfall across parts of Tamil Nadu over the coming days, driven by an active weather system over the Bay of Bengal. The advisory, issued on Sunday, 18 May, puts five districts on alert for significant downpours.
Districts Under Heavy Rainfall Alert
The districts of Theni, Dindigul, Madurai, Coimbatore, and the Nilgiris are forecast to receive heavy rainfall on Sunday and Monday. Additionally, Karur, Tiruchy, and Sivaganga districts have been placed on alert for heavy showers on Monday.
The trigger is a low-pressure area persisting over the southwest Bay of Bengal, which meteorologists expect to sustain rainfall activity across interior and western Tamil Nadu for at least three more days. This follows welcome summer showers that drenched several parts of the state on Saturday, providing temporary relief from intense heat.
Thunderstorms, Lightning and Gusty Winds Likely
Beyond rainfall, the IMD has warned of thunderstorms accompanied by lightning and gusty winds reaching up to 40 kmph at isolated locations during active spells. Residents in the affected districts have been advised to stay indoors during peak weather activity and to follow updates from local authorities closely.
Chennai and its suburban areas are expected to see light to moderate rainfall through the day, with cloudy skies and occasional spells likely to ease temperatures, though widespread heavy showers are not anticipated for the city itself.
Fishermen Warned Off Several Sea Zones
The weather department has issued a separate advisory urging fishermen not to venture into several sea regions until conditions improve. Strong winds of up to 60 kmph are expected over south Tamil Nadu coastal areas, the Gulf of Mannar, the Kanyakumari Sea region, the Andaman Sea, and parts of the south Bay of Bengal. Coastal residents have also been urged to remain alert and adhere strictly to safety guidelines.
Monsoon Onset and What It Means
The IMD's formal declaration of the southwest monsoon's onset marks a significant seasonal shift for Tamil Nadu. The state's western ghats districts — including the Nilgiris and Coimbatore — typically receive the season's first heavy spells as moisture-laden winds push inland from the Arabian Sea and Bay of Bengal convergence. This year's onset comes amid a broader pattern of above-normal pre-monsoon activity across peninsular India.
Authorities are expected to continue issuing rolling advisories as the low-pressure system evolves over the next 72 hours.
Point of View
But the clustering of alerts across both interior districts and coastal zones signals that this system has broader reach than a routine pre-monsoon squall. What deserves closer attention is the fishermen advisory — rough seas in the Gulf of Mannar and south Bay of Bengal can ground livelihoods for days, and the economic impact on coastal communities rarely features in weather coverage. The IMD's three-day sustained rainfall forecast also raises the question of flood preparedness in low-lying areas of Madurai and Dindigul, districts that have seen inundation in recent monsoon seasons.
NationPress
4 Jul 2026
Frequently Asked Questions
Which Tamil Nadu districts are under heavy rain alert?
The IMD has placed Theni, Dindigul, Madurai, Coimbatore and the Nilgiris on heavy rain alert for Sunday and Monday. Karur, Tiruchy and Sivaganga are additionally forecast to receive heavy rainfall on Monday.
Why is Tamil Nadu receiving heavy rain right now?
A low-pressure area persisting over the southwest Bay of Bengal is driving the rainfall activity. The IMD has also declared the official onset of the southwest monsoon, which is bringing moisture-laden winds into the region.
How long will the heavy rainfall last in Tamil Nadu?
According to the IMD, the low-pressure system is expected to sustain rainfall activity for at least three more days from Sunday, 18 May. Rolling advisories are expected as the system evolves.
What is the warning for fishermen in Tamil Nadu?
The IMD has advised fishermen not to venture into south Tamil Nadu coastal waters, the Gulf of Mannar, the Kanyakumari Sea region, the Andaman Sea, and parts of the south Bay of Bengal. Winds of up to 60 kmph are expected in these zones.
Will Chennai receive heavy rain?
Chennai is expected to see light to moderate rainfall with cloudy skies and occasional spells. The city is not forecast to receive widespread heavy showers, but residents can expect some relief from rising temperatures.
