Various parts of Tamil Nadu and Pondicherry, including the metropolis, experienced intermittent rains since Saturday night, in the wake of a deep depression crossing over Vedaranyam in Nagapattinam district.
Saturday's deep depression has further weakened and now lay as a low pressure over south coastal Tamil Nadu and adjoining regions, the weather department said in Chennai on Sunday.
As a result, rains or thundershowers were likely over many places in Tamil Nadu and Pondicherry during the next 48 hours, beginning from 8.30 am on Sunday morning, the department added.
Isolated heavy rains have also been forecast over some places during the same period, the weather office said, adding that the metropolis was likely to experience few rain spells or thundershowers.
At Vedaranyam, rains have inundated paddy fields and low lying areas, and caused damage to the roads.
More than 30,000 people had been moved to 51 relief centres, a report said.