All cities in the top 10 list recorded higher PM2.5 levels than the previous year, except for Delhi.

"Delhi ranked as the fourth most polluted city, recording a monthly average PM2.5 concentration of 215 µg/m³ in November, about twice its October level of 107 µg/m³. The city experienced 23 ‘Very Poor’ days, six ‘Severe’ days, and one ‘Poor’ day throughout November," the report stated.

Despite widespread pollution, the contribution of stubble burning was an average of 7 per cent in November, down from 20 per cent last year. Peak contributions of stubble burning reached 22 per cent, significantly lower than 38 per cent recorded in the previous year.

"Except for Bahadurgarh, none of the top ten cities recorded even a single day within the safe daily NAAQS limit. Several other cities, including Charkhi Dadri, Bulandshahr, Jind, Muzaffarnagar, Gurgaon, Khurja, Bhiwani, Karnal, Yamunanagar and Faridabad, also recorded PM2.5 levels above NAAQS every day of the month. Sonipat recorded ‘very poor' air quality with PM 2.5 at 121-250 µg/m³ on 29 of the 30 days, while Bahadurgarh remained the second most polluted with a PM 2.5 average of 215 µg/m³," it added.

While seven cities of Punjab exceeded the standard as Mandi Gobindgarh was the most polluted in Punjab with PM 2.5 at 93 µg/m³.

"Despite a significant reduction in stubble-burning influence, 20 out of 29 NCR cities recorded higher pollution levels than the previous year, and many still did not register a single day within NAAQS limits. This clearly indicates that the dominant drivers are year-round sources such as transport, industry, power plants, and other combustion sources. Without sector-specific emission cuts, cities will continue to breach standards," said Manoj Kumar, analyst at CREA.

At the state level, Rajasthan had the largest number of polluted cities, with 23 of 34 exceeding the NAAQS in November. Haryana had 22 of 25 such cities, while Uttar Pradesh had 14 of 20 above the standard. Pollution levels were also high across other states, with 9 of 12 cities in Madhya Pradesh, 9 of 14 in Odisha, and 7 of 8 in Punjab recording concentrations above NAAQS.