Chennai had on Thursday witnessed an unpredicted and unprecedented rainfall that had inundated most parts of the city and caused major traffic gridlock. The incessant downpour has cast a sudden disruption to normal lives and the rainfall has become an alarm that the city must fix its flawed measures and challenges to mitigate inundations. The intense half-a-day rainfall has broken the figures that were recorded during the Chennai floods in 2015.

The city has reported three deaths on Thursday due to heavy rainfall and all three had died due to electrocution. The deceased include two women and a young man. Tamil Nadu Minister for Revenue and Disaster Management KKSSR Ramachandran had said about the deaths and Chief Minister MK Stalin had reviewed the situation along with the authorities at around 11.45 pm on Thursday. The disruption has been at a large scale and the city's police department has said that three subways in T Nagar, Egmore, and Rajaji Salai were closed due to inundation.

The visuals from important stretches of the city including Anna Salai had shown vehicles were crawling and the disruption remained intact for several hours with many people had returned back to their place of origin after finding it difficult to reach home. The sudden downpour had led the residents to rely on metro trains to reach their home and the Chennai Metro management had extended train services by an hour after 11 pm on Thursday. Hundreds of people were seen marching towards the metro station. 

The Greater Chennai Corporation has used over 145 pumps to pump out water from the inundated areas and the India Meteorological Department (IMD) has said that the highest rainfall of 21.4 cm was recorded in MRC Nagar while it was 14.8 cm at Meenambakkam as per the IMD data at 5.30 am on December 31. As the sequel of the rainfall, the Tamil Nadu government had declared holidays in four districts on Friday- December 31. 

Apart from the essential services, the government had declared a holiday on Friday for schools, colleges, and non-essential government offices in the four districts of Chennai, Tiruvallur, Chengalpattu, and Kanchipuram. For Friday, the Meteorological Department has forecast thunderstorms with light to moderate rain at places over Kanchipuram, Chengalpattu, Tiruvannamalai, Villupuram, Cuddalore, Mayiladuthurai, Nagapattinam, Pudukottai, Tiruchirapalli, Thanjavur, Tiruvarur, Sivaganga, Ramanathapuram, and Ariyalur districts. 

A red alert of very heavy rainfall has been issued to Chennai and its three adjacent districts of Kanchipuram, Chengalpattu, and Tiruvallur. As the city is going to end the year with heavy downpour, S Balachandran, Deputy Director-General of IMD has said, "The interaction of easterly winds at lower levels and westerly winds at upper level has brought rain to the city. The rains in the city will continue till January 3." Puviarasan, the Director of Area Cyclone Warning Centre has said, "The unexpected fast movement of the easterly trough over Chennai coast has led to intense rainfall in the city on Thursday. Prediction of such heavy rains is impossible."