Day after Diwali, Delhi records worst air quality in 5 years

The air quality in Delhi plummeted on Tuesday post Diwali as residents flouted the Supreme Court-mandated time slots for bursting of firecrackers, even as the city government blamed the AAP dispensation in Punjab for the toxic haze over the national capital alleging forced stubble-burning on Monday night.

The city recorded its worst air quality on Tuesday since 2021, with PM2.5 levels reaching 488 micrograms per cubic metre in the 24 hours after Diwali, more than three times the pre-festival level of 156.6 micrograms per cubic metre.

In neighbouring Haryana too, the air quality deteriorated with the AQI falling in the 'very poor' category in many areas, including in Gurugram, while it was in the 'poor' category in most parts of Punjab.

According to an analysis of Central Pollution Control Board (CPCB) data covering the period from 2021 to 2025, PM2.5 values in Delhi consistently spiked during Diwali night and early the next morning, with the 2025 post-Diwali reading of 488 micrograms per cubic metre being the most polluted period since 2021.

The data shows that in previous years, average PM2.5 levels rose from 163.1 to 454.5 in 2021, from 129.3 to 168 in 2022, from 92.9 to 319.7 in 2023 and from 204 to 220 in 2024.

The study by research and advisory group Climate Trends attributed the surge mainly to local emissions from firecrackers, stagnant winds of less than one metre per second and temperature inversion that traps pollutants close to the surface.

The high concentration of PM2.5 is due to local firecracker emissions across different parts of Delhi. Wind speed was extremely low, leaving no scope for dispersion, said S K Dhaka, professor at Rajdhani College, University of Delhi.

He added that even "so-called" green firecrackers contributed significantly to particulate buildup and there was a need to check their quality and composition.

Experts said the continuing rise in pollution levels despite restrictions shows both enforcement gaps and public disregard for health warnings.

Delhi found itself enveloped in a thick grey haze, reduced visibility, and its air quality into the 'red zone' on Tuesday.

Addressing a press conference, Environment Minister Manjinder Sirsa accused the Aam Aadmi Party of "playing politics".

The minister claimed that the real reason behind the worsening air quality was large-scale stubble-burning in Punjab.

Sirsa said that every religion has the right to celebrate its festival, indicating that bursting of crackers is an indispensable way of celebrating Diwali.

He stressed that despite the lifting of the ban on green firecrackers this year, Delhi's air quality index (AQI) rose only marginally, from 345 before Diwali to 356 the next morning, an increase of "just 11 points".

Last year, it increased by 32 units and in 2023 by 83 units, he pointed out.

"This little increase of just 11 points was observed this year even though it was reported that the highest number of stubble-burning incidents occurred last night," he said, showing videos purportedly of burning of crop residue in Punjab.

Unfavourable meteorological conditions, combined with vehicular emissions, paddy-straw burning, firecrackers, and other local pollution sources, contribute to hazardous air quality levels in Delhi-NCR during winters.

The capital's air quality has consistently fallen into the 'severe' category (AQI above 400) after Diwali for most of the past decade, despite court bans on firecrackers and repeated advisories from authorities.