Delhi recorded its most polluted Diwali in five years, with the city’s average Air Quality Index reaching 376, while the post-Diwali reading remained in the ‘very poor’ category at 371 by 10 am on Monday. The combination of dense fog, calm winds and continued local pollution left large parts of the capital under a thick layer of smog.
The post-Diwali AQI of 371 was the highest recorded for the day after the festival since 2021, according to Central Pollution Control Board data cited in the report. Of 51 monitoring stations that recorded data, 14 were in the ‘severe’ category, four were in the ‘poor’ category and 33 were in the ‘very poor’ category. Delhi Technological University recorded the worst reading at 439.
The city’s overall AQI had stood at 370 at 8 am. The Diwali-day average of 376 was below the 382 recorded in 2021 but higher than the corresponding readings in 2022, 2023, 2024 and 2025. The average AQI on Diwali was 312 in 2022, 218 in 2023, 328 in 2024 and 345 in 2025.
Pollution also remained elevated after the festival. The full-day AQI on the day after Diwali was 462 in 2021, 302 in 2022, 360 in 2023, 338 in 2024 and 351 in 2025. The comparison is complicated by the fact that Diwali falls on different dates each year, ranging from October 20 in 2025 to November 8 in the year covered by the report.
The India Meteorological Department recorded sharply reduced visibility in the morning. At Safdarjung, visibility fell to 50 metres at 6.30 am, compared with 700 metres a day earlier. At Palam, visibility was 400 metres, down from 800 metres on Sunday. Visibility later improved, reaching 500 metres at Safdarjung and 900 metres at Palam by 9 am.
Safdarjung experienced shallow fog from 10.30 pm to 2.30 am before dense fog persisted for six hours and 30 minutes until 9 am. Palam recorded shallow fog from midnight to 5 am, followed by moderate fog for three and a half hours. IMD officials described the conditions as “smog along with fog” and attributed the hazy conditions and the drop in AQI from the previous night to dry weather and calm winds.
Independent air-quality platforms also reported hazardous conditions, although their readings differed from the CPCB figure. Swiss platform IQAir placed Delhi in the ‘very unhealthy’ category with an AQI of 245 at 8.30 am and reported PM2.5 concentration at 170 micrograms per cubic metre, around 34 times the World Health Organisation’s annual guideline value. AQI.in recorded readings as high as 2,283 after Diwali and 637 on Monday morning.
Several areas, including Bawana, Burari, Jahangirpuri, Sonia Vihar, Punjabi Bagh, Okhla and Rohini, continued to record severe air quality. Fireworks were reported in parts of Pitampura, Burari, Mayur Vihar and Lutyens’ Delhi despite restrictions.
An order from the District Magistrate (East) permitted only green firecrackers on November 7 and 8, between 6 am and 7 am and 8 pm and 10 pm. The order also prohibited fireworks within 300 metres of hospitals, nursing homes, health centres, old-age homes, educational institutions and other notified silence zones. Only CSIR-NEERI-certified green firecrackers were permitted for sale at locations designated by the Delhi Police in coordination with the district administration.
