Delhi woke shrouded in an alarming level of air pollution on Monday, November 9, after a night of Diwali celebrations and firecracker bursts pushed the city's air quality to an extraordinary high.
Delhi's Air Quality Index (AQI) stood at 663 at 8:01 am, after touching a peak of 1,331 at 1:31 am, according to AQI.in data. It may be noted that the readings cited in this report are based on AQI.in's real-time data and are separate from the official AQI figures published by the Central Pollution Control Board (CPCB).
This morning's reading was nearly 69% higher than the AQI.in a reading of 393 recorded on October 21, 2025, the day after Diwali last year. The comparison between the two post-Diwali pollution in the capital paints a worrying picture for those residing in Delhi-NCR, showing how much worse the post-festival pollution has become in just a year.
AN OVERNIGHT RISE IN POLLUTION
The data shows that pollution in Delhi rose late on Sunday, with the steepest rise beginning around 10 pm. The air quality was already bad at 9:31 pm, when it was recorded to be at 681. Then it skyrocketed, touching 1,153 by 11 pm and soon reaching its highest recorded level of 1,331 at 1:31 am.
The toxic air gradually eased through the early morning, and even then remained at 663.
The rise came after days of already poor air quality, leading up to Diwali.
Delhi's pollution had been worsening well before Diwali, leaving little room for the city to absorb another burst of smoke.
On November 8, the day of the festival, the official CPCB 24-hour AQI was 376, in the 'very poor' category. The official forecast had warned that air quality could turn 'severe' on November 9.
On November 3, Delhi's AQI.in reading had climbed from 124 on October 30 to 393 on November 2, before reaching 464 by 11:31 am on November 3.
The brief improvement after late-October rain and strong winds had quickly disappeared as dry conditions returned and pollution from vehicles, industries, construction, road dust and waste burning accumulated.
Diwali added another layer to this already toxic mix. Firecrackers release smoke and fine particles into the air, while weak winds and unfavourable weather make it harder for these pollutants to disperse.
Furthermore, smoke from crop-residue burning in neighbouring states can add to the burden during this time of year.
The Commission for Air Quality Management had already brought Stage III restrictions under the Graded Response Action Plan (GRAP) into force across Delhi-NCR on November 6, as pollution worsened ahead of the festival.
With the pollution touching sky-high levels, residents have a long, polluted week ahead of them.
Source: India Today