3 min read Kolkata Updated: Nov 9, 2026 05:23 PM IST

West Bengal has tightened festive safety rules for Diwali, Kali Puja and Chhath, restricting cracker timings and enforcing crowd control and fire safety measures. (File photo)

Written by Sharanyo Basu

Kolkata ’s air quality plummeted to hazardous levels on Diwali and Kali Puja night, hitting an Air Quality Index (AQI) of 623 at 11 pm on Sunday, according to aqi.com, an online monitoring system that follows US standards. At the same time, the Central Pollution Control Board (CPCB), which follows Indian standards, recorded a moderate average citywide AQI of 154, with Jadavpur hitting 176.

CPCB data showed a steady decline through the night, bringing the citywide average to 173 by 4 am on Monday.…