CHENNAI: For the next seven days, Tamil Nadu and Puducherry can expect a mix of light to moderate rain with thunderstorms at isolated places, with specific heavy rain warnings issued for coastal and interior districts like Tiruvallur, Kancheepuram, Vellore, and Ranipet at the start of the period. Gusty winds up to 40 kmph may occur with these storms. The region is transitioning into the pre-northeast monsoon season, which is expected to bring increased thunderstorm activity.
Here’s a breakdown of the forecast:
Day 1
(16.09.2025)
Light to moderate rain at a few places with thunderstorm and lightning with gusty winds speed reaching 30-40 kmph at one or two places is likely to occur over Tamilnadu, Puducherry and Karaikal area.
Heavy rain is likely to occur at isolated places over Erode, Salem, Dharmapuri, Krishnagiri, Vellore, Tiruvannamalai, Tirupattur, Chengalpattu, Villuppuram and Kallakurichi districts and Puducherry.
Day 2
(17.09.2025)
Light to moderate rain at many places with thunderstorm and lightning with gusty winds speed reaching 30-40 kmph at one or two places is likely to occur over Tamilnadu, Puducherry and Karaikal area.
Heavy rain is likely to occur at isolated places over Mayiladuthurai, Nagapattinam, Tiruvarur, Thanjavur, Pudukkottai, Sivaganga, Tiruchirappalli, Madurai, Theni, Dindigul, Nilgiris, Erode, Krishnagiri, Dharmapuri, Salem, Tirupattur, Tiruvannamalai, Chengalpattu and Kancheepuram districts and Karaikal area.
Day 3
(18.09.2025)
Light to moderate rain at many places with thunderstorm and lightning with gusty winds speed reaching 30-40 kmph at one or two places is likely to occur over Tamilnadu, Puducherry and Karaikal area.
Heavy rain is likely to occur at isolated places over Nilgiris, Erode, Krishnagiri, Dharmapuri, Salem, Tiruvannamalai, Tirupattur, Vellore, Kallakurichi, Chengalpattu and Kancheepuram districts.
Day 4
(19.09.2025)
Light to moderate rain at a few places with thunderstorm and lightning with gusty winds speed reaching 30-40 kmph at one or two places is likely to occur over Tamilnadu, Puducherry and Karaikal area.
Heavy rain is likely to occur at isolated places over Tiruvallur, Ranipet, Vellore and Kancheepuram districts.
Day 5
(20.09.2025)
Light to moderate rain at isolated places with thunderstorm and lightning with gusty winds speed reaching 30-40 kmph at one or two places is likely to occur over Tamilnadu, Puducherry and Karaikal area.
Day 6
(21.09.2025)
Light to moderate rain is likely to occur at isolated places over Tamilnadu, Puducherry and Karaikal area.
Day 7
(22.09.2025)
Light to moderate rain is likely to occur at isolated places over Tamilnadu, Puducherry and Karaikal area.
HEAVY RAINFALL WARNING:
Day 1
(16.09.2025)
Heavy rain is likely to occur at isolated places over Erode, Salem, Dharmapuri, Krishnagiri, Tirupattur, Vellore, Tiruvannamalai, Chengalpattu, Villuppuram and Kallakurichi districts and Puducherry.
Day 2
(17.09.2025)
Heavy rain is likely to occur at isolated places over Mayiladuthurai, Nagapattinam, Tiruvarur, Thanjavur, Pudukkottai, Sivaganga, Tiruchirappalli, Madurai, Theni, Dindigul, Nilgiris, Erode, Krishnagiri, Dharmapuri, Salem, Tirupattur, Tiruvannamalai, Chengalpattu and Kancheepuram districts and Karaikal area.
Day 3
(18.09.2025)
Heavy rain is likely to occur at isolated places over Nilgiris, Erode, Krishnagiri, Dharmapuri, Salem, Vellore, Tiruvannamalai, Tirupattur, Kallakurichi, Chengalpattu and Kancheepuram districts.
Day 4 Heavy rain is likely to occur at isolated places over Tiruvallur, Ranipet,
(19.09.2025) Vellore and Kancheepuram districts.
THUNDERSTORM WARNING
Day 1
(16.09.2025)
to
Day 5
(20.09.2025)
Thunderstorm and lightning with gusty winds speed reaching 30-40 kmph is likely to occur at one or two places over Tamilnadu, Puducherry and Karaikal area.
TEMPERATURE FORECAST
Gradual fall in maximum temperature by 2-3°C at a few pockets over Tamilnadu, Puducherry and
Karaikal during next 3 days Day 1 (16.09.2025) to Day 3 (18.09.2025).
Slight rise in maximum temperature at a few pockets over Tamilnadu, Puducherry and Karaikal on Day
4 (19.09.2025).
Departure from normal:
Maximum Temperature is likely to be above normal by 2-3°C at isolated pockets during Day 1
(16.09.2025) and thereafter near normal to slightly below normal during Day 2 (17.09.2025) to Day
4 (19.09.2025) over Tamilnadu, Puducherry and Karaikal area.
