Delhi Pollution Control Committee (DPCC) report released on Monday late night claimed a marginal improvement in air quality the morning after Diwali, with its Air Quality Index (AQI) declining to 371 from 382, while noise levels on the festival day rose at 19 of the city's 26 monitoring locations compared to last year. The report showed a 2.9 per cent fall in AQI at 10 am on Monday, the morning after Diwali, compared to other years, due to meteorological factors, and also cited higher wind speeds as the reason.
However, both the Diwali-day and post-Diwali readings were the highest for the corresponding mornings in the four-year comparison presented in the report. Meanwhile, noise levels on Diwali ranged from 57.5 dB(A) at Najafgarh to 89.1 dB(A) at Karol Bagh, with 19 locations recording an increase in noise level as compared to 2025 and seven registering a decline, the report said. Karol Bagh remained the noisiest of the monitored locations despite a marginal decline from 89.2 dB(A) last year.
Other locations recording relatively high levels included Jahangirpuri at 81.2 dB(A), Dwarka at 79.8 dB(A), Patparganj at 79.5 dB(A) and Vivek Vihar at 79.3 dB(A). Sonia Vihar registered the largest rise in the reported decibel reading, from 64.3 dB(A) in 2025 to 74.9 dB(A) in 2026. Levels also increased at Jahangirpuri from 74 to 81.2 dB(A), Mundka from 62.5 to 68.2 dB(A), and Patparganj from 73.3 to 79.5 dB(A).
Ashok Vihar recorded the largest decline, from 74.9 dB(A) to 68.3 dB(A).
The other locations reporting lower readings were Rohini, Vivek Vihar, Connaught Place, Dr Karni Singh, Karol Bagh and Pusa, the report said.
Delhi's AQI fell by 11 points between 10 am on Diwali, November 8, and the same time on November 9, according to the report's principal comparison.
Morning wind speeds increased from 5-10 kmph to 10-15 kmph, it said, “Overall Ambient Air Quality of Delhi showed minor improvement in terms of AQI due to meteorological factors,” the committee said in its conclusion.