Delhi's AQI stood at 371 on November 9, with 14 monitoring stations recording severe pollution.
Delhi recorded its highest Diwali-day AQI since 2021, at 376.
Crop-residue burning incidents across Punjab, Haryana, Uttar Pradesh and Delhi rose to 1,248 on Diwali.
Delhi’s air quality remained in the very poor category on Tuesday morning, November 10, with the overall AQI standing at 311 as of 6 am. Chandni Chowk recorded the highest reading at 400, followed by Pusa at 398.
The reading is in line with the Air Quality Early Warning System’s forecast that air quality would stay in the very poor category on November 10 and 11 due to unfavourable meteorological conditions.
Delhi had recorded an average AQI of 376 at 4 pm on Diwali, November 8 — its highest festival-day reading since 2021 — and 371 at 10 am on Monday, when 14 monitoring stations were in the severe category.
Delhi Records Highest Diwali AQI Since 2021
Of the 51 monitoring stations reporting data at 10 am on Monday, 14 recorded severe air quality, four were in the poor category and the remaining 33 registered very poor air quality, PTI reported. Delhi Technological University (DTU) recorded the highest AQI at 439. The city's AQI had stood at 370 at 8 am before rising to 371 at 10 am.
Delhi's Diwali-day AQI of 376 was its highest festival-day reading since 2021, when the AQI stood at 382, PTI reported. The corresponding readings were 345 in 2025, 328 in 2024, 218 in 2023 and 312 in 2022. The AQI at 4 pm on the day after Diwali was 351 in 2025, 338 in 2024, 360 in 2023, 302 in 2022 and 462 in 2021.
Visibility also deteriorated across the capital on Monday morning. At Safdarjung, visibility dropped to 50 metres at 6.30 am, compared with 700 metres a day earlier. At Palam, it fell to 400 metres from 800 metres on Sunday. IMD officials described the conditions as "smog along with fog".
The DPCC, in its assessment cited by PTI, attributed the marginal improvement in morning air quality to meteorological factors. "Overall Ambient Air Quality of Delhi showed minor improvement in terms of AQI due to meteorological factors," the committee said. Morning wind speeds had increased from 5–10 kmph to 10–15 kmph.
Crop-residue burning adds to Delhi's pollution burden
The DPCC assessment also recorded high particulate matter concentrations on Diwali. The 24-hour city-average PM10 concentration stood at 682 micrograms per cubic metre, while PM2.5 was recorded at 473 micrograms per cubic metre. The corresponding figures in 2025 were 703 and 520 micrograms per cubic metre, respectively. The figures indicate a roughly 3 per cent decline in PM10 concentrations from 2025, although the DPCC report's accompanying text described the reduction as 30 per cent. PM2.5 levels fell by around 9 per cent over the same comparison.
PTI also reported that 1,248 crop-residue burning incidents were recorded across Punjab, Haryana, Uttar Pradesh and Delhi on Diwali, compared with 135 on the festival day last year. Punjab accounted for 1,152 incidents, Haryana for 80 and Uttar Pradesh for 16, while Delhi reported none.
The Air Quality Early Warning System identified unfavourable meteorological conditions, vehicular emissions, Diwali celebrations and crop-residue burning as factors expected to contribute to the deterioration in air quality. Stage III of the Graded Response Action Plan (GRAP) has been in force across Delhi-NCR since November 6, after the Commission for Air Quality Management (CAQM) invoked the restrictions in anticipation of worsening air quality. The measures include curbs on non-essential construction and demolition activities.
