Having remained mostly satisfactory all through the year, the city’s air quality deteriorated to the “very poor” category on Diwali night as revellers continued bursting firecrackers late into the night, even as the administration had set a two-hour window – 8 pm to 10 pm – for fireworks.
The Air Quality Index (AQI) touched 326 – the highest in the city– at Sector 25 around midnight, while three of the city’s six monitoring stations recorded readings above 300, according to data shared by the Chandigarh Pollution Control Committee (CPCC).
An AQI between 301 and 400 is classified as “very poor” and can cause respiratory illness on prolonged exposure.
The monitoring station at PEC, Sector 12, recorded a high of 312 while the one at IMTECH, Sector 39, logged 310, and Sector 53 saw it rise to 304. Sector 22 recorded readings of 158 and 170, both falling in the moderate category. Moderate air can cause breathing discomfort to people with lung or heart diseases and those suffering from asthma.
Most monitoring stations had recorded satisfactory or moderate readings in the week preceding Diwali.
In the official statement, however, UT director (environment) and CPCC member secretary Saurabh Kumar maintained that there was an improvement. “This year, the air quality levels saw an improvement, and further improved the day after Diwali. The credit goes to residents for bursting fewer crackers, and to the weather conditions that dispersed the pollutants quickly,” he said.
At 7 pm on Monday – the evening after Diwali – the city’s AQI stood at 160, in the moderate category. Sector 22 recorded the highest reading at 183, while Sector 53 reported the lowest at 119. More improvement can be expected later in the week when light rains are likely.
While Mohali lacks a dedicated air quality monitoring station and depends on Chandigarh to assess its pollution levels, the AQI reading for Panchkula on Diwali was not available on the CPCB website, even though the Haryana State Pollution Control Board has an observatory in Sector 6. Panchkula’s average AQI at 9 pm on Monday was 170, in the moderate category. The average AQI stood at 48 on November 7 and 59 on November 6.
Chandigarh recorded its highest Diwali noise levels in three years at several monitoring locations, with IMTECH registering a peak of 83.9 dB(A) between 9 pm and 10 pm on November 8.
Sector 22 followed with 81.3 dB(A), while Sector 17 and PEC, Sector 12, both recorded 73.2 dB(A). Sector 25 registered 71.6 dB(A), while Sector 53 recorded 66.1 dB(A).
The readings were substantially higher than the prescribed ambient noise standards of 55 dB(A) during daytime (6 am to 10 pm) and 45 dB(A) during night-time (10 pm to 6 am).
A comparison with previous years showed a significant increase at IMTECH, where the reading during the 9 pm to 10 pm period stood at 83.9 dB(A), against 74.3 dB(A) in 2025, 66.1 dB(A) in 2024 and 72.4 dB(A) in 2023. Sector 22 recorded 81.3 dB(A), marginally higher than 80.7 dB(A) last year.
The CPCC said noise levels declined at most locations after the permitted cracker-bursting window ended at 10 pm. Kumar said the committee would review the data and work on reducing noise pollution during next year’s Diwali celebrations.
While UT police had deployed over 800 personnel on the ground to maintain law and order on Diwali night, the police control room received 494 Diwali-related calls. Of these, 203 were cracker-related incidents and 34 were linked to minor fire incidents. Police officials maintained that no action had been taken against anyone for violating the 10 pm deadline for bursting crackers. Neighbours Panchkula and Mohali too, took no action against the deadline violations. Mohali police, however, reported issuing 1,267 traffic challans on Diwali.
Two major fire incidents were also reported in Mohali during the festivities. In one case, 18 vehicles were gutted in a blaze at an old-car sale and purchase dealership on Airport Road. In the second, six to seven vehicles were gutted in a fire at a motor spare parts garage near TDI Khalsa Dhaba in Mohali.
S Jarnail Singh, vice-president of Senior Citizens Mohali, said, “It is ultimately the responsibility of residents to follow the rules. People should be aware enough to understand the need to celebrate responsibly and do the right thing.”
In Chandigarh, meanwhile, a case under the Explosives Act was registered at the Sector 26 police station. The accused, Mohammad Mukeem (56), a resident of Bapu Dham Colony, Sector 26, was caught near his house on Diwali. Banned firecrackers were recovered from his possession during a search. He was arrested and later released on bail. The case was registered under Sections 223 (disobedience to public servant’s order) and 288 (negligent conduct with explosives) of the Bharatiya Nyaya Sanhita (BNS), along with provisions of the Explosives Act.