The trend of cooler than normal nights in Chennai and other parts of North Tamil Nadu has got a break with nights set to become warmer under the influence of weak Easterlies that is set set influence Coastal Tamil Nadu over the next few days. While the Easterlies are unlikely to be strong enough to bring heavy rains or widespread spells they will certainly increase the humidity and night time temperatures in the coastal areas of Tamil Nadu
The last few days saw most of Tamil Nadu come under the influence of Land breeze from West / Northwest thanks to the High Pressure that was holding sway. This has now given way to more Easterlies from early morning today bringing in the possibility of possible light showers for Coastal Tamil Nadu.
Overall though since the atmosphere is in fairly subdued condition the rains are unlikely to be heavy or widespread. Since the rains will be like Northeast Monsoon period we are likely to see spells of rains after midnight around early morning in the coastal areas including Chennai. The places to the South of Pondicherry around the Delta region could possibly receive better spell of these rains.