IMD forecasts heavy rain in Tamil Nadu from July 30; Nilgiris, Coimbatore, Theni on alert
Synopsis
A weak atmospheric trough along the Tamil Nadu coast is set to trigger heavy rainfall in Nilgiris, Coimbatore, and Theni from July 30, with the wet spell peaking on July 31 and continuing into August 1. Chennai will see partly cloudy skies and light showers, while temperatures across the state stay 2°C–4°C above normal at select locations.
Key Takeaways
The IMD has forecast heavy rainfall in Tamil Nadu driven by a weak trough along the coast, intensifying from July 30 .
Nilgiris , Coimbatore , and Theni districts are on alert for heavy rain at isolated places on July 31 and August 1 .
Moderate rain and thunderstorms are expected across Western Ghats districts and north coastal Tamil Nadu through the week.
Chennai will see partly cloudy skies with daytime temperatures between 38°C and 39°C and light rain likely.
Temperatures at a few places may remain 2°C to 4°C above normal until July 31 , with no significant change forecast before then.
The India Meteorological Department (IMD) has forecast heavy rainfall across parts of Tamil Nadu over the next three days, with Nilgiris, Coimbatore, and Theni districts expected to receive intense showers from July 30 onwards. The weather agency has attributed the changing conditions to a weak trough persisting in the lower atmospheric levels along the Tamil Nadu coast.
District-wise Forecast
On Tuesday, moderate rainfall accompanied by thunderstorms and gusty winds is expected at one or two places across north coastal Tamil Nadu, the Western Ghats districts, and Puducherry. Similar conditions are likely to continue on Wednesday and Thursday, with moderate rain and thunderstorms at isolated locations across the Western Ghats.
Rainfall activity is forecast to intensify from July 30, when heavy rain is expected at isolated places in the Nilgiris, while moderate showers are likely over other Western Ghats districts. Light rain may also occur in isolated areas across the rest of Tamil Nadu and Puducherry.
Peak Wet Spell: July 31 to August 1
On July 31, heavy rainfall is forecast at isolated places in Coimbatore, Nilgiris, and Theni districts. Moderate rain is expected in other Western Ghats districts, while light showers may occur in remaining parts of Tamil Nadu and Puducherry.
The wet spell is set to continue on August 1, with Coimbatore, Nilgiris, and Theni again likely to receive heavy rain at isolated locations. Moderate showers are also expected over interior Tamil Nadu, north coastal districts, Puducherry, and Karaikal, with light rain elsewhere.
Temperature Outlook
The IMD has indicated there is unlikely to be any significant change in maximum temperatures across Tamil Nadu and Puducherry until July 31. However, temperatures at a few places could remain 2°C to 4°C above normal, while the rest of the state is expected to record temperatures close to seasonal averages.
Chennai Weather
For Chennai, the IMD has forecast partly cloudy skies on Tuesday and Wednesday, with light rain and thunderstorms likely in a few parts of the city. Daytime temperatures are expected to hover between 38°C and 39°C, while the minimum temperature is likely to remain between 29°C and 30°C.
The IMD has said moderate rainfall is likely to persist over Western Ghats districts and north coastal Tamil Nadu in the days ahead, with light rain expected elsewhere across the state. Residents in high-rainfall districts are advised to remain alert as conditions intensify through the end of the week.
Point of View
But the concentration of heavy-rain alerts in Nilgiris, Coimbatore, and Theni — districts that sit along ecologically sensitive Western Ghats terrain — warrants attention beyond the weather bulletin. These are the same districts where landslides and flash floods have caused fatalities in recent years during peak monsoon weeks. The absence of any district-administration advisory or NDRF pre-positioning detail in the current forecast cycle is a gap that authorities should close before July 31. Above-normal temperatures running alongside heavy-rain episodes also raises the risk of localised convective storms that are harder to predict and faster to turn dangerous.
NationPress
28 Jul 2026
Frequently Asked Questions
Which districts in Tamil Nadu are on heavy rain alert?
The IMD has placed Nilgiris, Coimbatore, and Theni districts on heavy rain alert, with intense showers expected at isolated locations from July 30 through August 1. Other Western Ghats districts are forecast to receive moderate rainfall during the same period.
What is causing heavy rain in Tamil Nadu this week?
The IMD has attributed the rainfall to a weak trough persisting in the lower levels of the atmosphere along the Tamil Nadu coast. This is a common monsoon-season trigger that enhances moisture influx over the Western Ghats and coastal districts.
What is the weather forecast for Chennai from July 28?
Chennai is forecast to have partly cloudy skies on Tuesday and Wednesday, with light rain and thunderstorms likely in a few areas. Daytime temperatures are expected to range between 38°C and 39°C, with night temperatures between 29°C and 30°C.
When will the rainfall in Tamil Nadu peak?
Rainfall activity is expected to intensify from July 30, with the peak wet spell on July 31 and August 1, when Coimbatore, Nilgiris, and Theni are forecast to receive heavy rain at isolated places.
Will temperatures change in Tamil Nadu during this wet spell?
The IMD does not expect any significant change in maximum temperatures across Tamil Nadu and Puducherry until July 31. A few locations may record temperatures 2°C to 4°C above normal, while most of the state is expected to remain close to seasonal averages.
