Heavy overnight rains in Chennai lashed many parts of the city after two days of near misses. The rains were pretty much confined to North Tamil Nadu as parts of Tiruvallur, Kanchipuram & Chennai districts recorded the bulk of rains last night. Ramakrishnaraju Pet (RK Pet) recorded 40 mm rains yesterday evening. Gusty winds accompanied by the Sound & light show marked the rains indicating the nature of the thunderstorms yesterday aided by atmospheric instability. 
Thanks to the overnight thunderstorms the temperatures have dropped in Chennai by almost 4 degrees compared to yesterday and is likely to play a role in the day time temperatures today as well. North Coastal Tamil Nadu is likely to see a day time maximum temperature of around 35 degrees today under cloudy skies which is likely to keep the temperature under check.
With the Upper Air Cyclonic Circulation that is lying off the coast of Andhra Pradesh playing a major role in how the weather events shape up over Peninsular India expect cloudy skies at many places over South India keeping temperatures under check over Andhra Pradesh & North Tamil Nadu. Mostly South India is likely to see normal or below normal temperatures except for parts of West Coast & South Tamil Nadu which is likely to see normal or slightly above normal temperatures.
Today we are likely to see moderate to heavy rains over parts of Coastal Andhra Pradesh thanks to the UAC while some parts of West Coast particularly around coastal Karnataka could get spells of heavy rains under monsoon surge. As things stand North Tamil Nadu could see isolated rains today though it is likely we could see much subdued rainfall activity compared to yesterday. Models indicate instability factor to be far lesser today in the region unlike yesterday which saw the thunderstorms get enhanced as the reached closer to the coast.
While we would not rule out Rains in Chennai today, as things stand a repeat of yesterday looks less likely.