Cyclone Nada weakened into a depression and made landfall near Nagapattinam between 4am and 5am on Friday morning.
Winds touched 50kmph when the system crossed the coast.
Rainfall is expected at various places in Tamil Nadu, Puducherry and Kerala.
According to the weather bulletin, light to moderate rainfall at many places with isolated heavy rainfall was expected over interior Tamil Nadu, and Kerala till Saturday. Light to moderate rainfall at many places is also likely over coastal Tamil Nadu and Puducherry till Friday night. IMD has also predicted that Chennai will receive light showers on Friday.
Squally winds speed reaching 40-50 kmph gusting to 60 kmph would prevail along and off Tamil Nadu and Puducherry coasts during next 12 hours.
The sea condition would be rough along and off Tamil Nadu and Puducherry coast and fishermen were advised not to venture into sea till Friday night.
A holiday was declared for schools in Chennai, Cuddalore, Kanchipuram, Tiruvallur and Nagapattinam on Thursday and Friday following the met departmentâ€™s cyclone Nada forecast.
The state government had also instructed all district collectors to take all precautionary measures and necessary actions including evacuating people from low lying and vulnerable areas to the relief centres.
Two teams of the National Disaster Response Force and one team of the state response force were positioned in Cuddalore, and one team each in Nagapattinam and Chennai as a precautionary measure since Wednesday.
The Navy was also on alert, with two naval ships on standby.
(With IANS inputs)