She said educational institutions in Chennai, Kancheepuram and Tiruvallur districts will remain closed for the second consecutive day tomorrow and quarterly exams in schools will be held later.
Jayalalithaa reviewed the situation with senior cabinet colleagues and officials and said various departments would work on war-footing to ensure people were not affected by the downpour with weather office forecasting heavy rains for another 24 hours.
The low pressure area over coastal Andhra Pradesh and adjoining West Central Bay of Bengal brought heavy overnight rains and thundershowers to the northern districts, leaving many low-lying areas inundated and affecting normal life in many parts, especially Chennai.
Heavy rains lashed various parts of the city, inundating low-lying residential areas, putting citizens to hardship. However, there was let up in the rains during the day in the city and suburbs.
The Regional Meteorological Centre here forecast more rains for the next 24 hours, starting 0830 am today.
A weather bulletin said rain or thundershowers would occur at many places over North Tamil Nadu and Puducherry.
Jayalalithaa in a statement said Collectors of respective northern districts were closely monitoring the situation and there was no damage due to rain so far, adding people will be provided with necessary relief immediately if required.
The Chief Minister said she has issued directives to various departments to take measures on war-footing in case there were floods.
Enough stock of medicines were available to prevent spreading of water-borne diseases like dengue and the Fire and Rescue Services Department will be on standby mode to attend to distress calls, she added.
With increased inflow into river Kollidam on account of heavy rains expected in Karnataka, officials were monitoring the situation there and so was the case with Veeranam lake in Cuddalore district in the state, she added.
"My government is prepared to face any kind of situation and all arrangements are in place to address flood-related damage," she said.