CHENNAI: Smog and poor visibility continued to blanket large parts of Chennai on Tuesday (October 21) morning, a day after Deepavali celebrations pushed air pollution levels to the year’s worst.

Several neighbourhoods in the city and outskirts recorded “very poor” to “severe” air quality through Monday night, with pollution monitors showing a sharp spike after 7 pm.

According to real-time data from the Central Pollution Control Board, the Air Quality Index (AQI) in Velachery touched 401 late on Monday (October 20) which categorised as “severe.” Perungudi and Chengalpettu recorded 331 and 342 respectively with almost every parts of the city and the outskirts including Tiruvanmiyur, Guindy, Kilpauk, Vyasarpadi, Manali have crossed beyond 250.

Though deteriorated, the situation appears "poor" in the next day with Arumbakkam standinh at 149, Velachery at 148, Perungudi at 197, and Kolathur at 128 on Tuesday morning.

Visibility on city roads dropped below 50 metres in several areas, and even underground metro stations and trains were shrouded in haze. The Tamil Nadu government had permitted cracker bursting only during two time slots there were zero enforcement on that regard.

In residential areas, the smell of smoke and burnt chemicals persisted well into the morning.

Last year, the city’s Valasaravakkam monitoring station had recorded an AQI of 287 on Deepavali day, while in 2023, it had touched 365. This year’s spike in southern and suburban zones, including Velachery and Perungudi, indicates a sharper rise compared to previous years.