Delhi recorded alarming levels of air pollution during Diwali night on November 8-9, 2026, with PM2.5 concentrations at one monitoring station reaching an astonishing 3,744 micrograms per cubic metre (µg/m³). This severe spike in pollution was initially obscured by the absence of 125 station-hours of data from the Central Pollution Control Board (CPCB) records, which were later made public by the Delhi Pollution Control Committee (DPCC).
Unprecedented PM2.5 Levels Recorded Across Delhi
The released hourly readings from the DPCC revealed that several monitoring stations across the capital city registered PM2.5 levels exceeding 2,000 µg/m³ in the early hours of November 9. The national 24-hour standard for PM2.5, fine particulate matter that can deeply penetrate the lungs, is 60 µg/m³. The recorded levels were many times higher than this safe limit.
- Mundka: Registered the highest PM2.5 level at 3,744 µg/m³ at 2:00 AM.
- JNU: Recorded 3,023 µg/m³ at 4:00 AM.
- NSUT West Campus: Hit 3,008 µg/m³ at 5:00 AM.
- Mandir Marg: Reached 2,908 µg/m³ at 3:00 AM.
- Nehru Nagar: Saw 2,808 µg/m³ at 3:00 AM.
- Wazirpur: Recorded 2,721 µg/m³ at 1:00 AM.
In total, eleven of DPCC’s stations reported PM2.5 levels above 2,000 µg/m³.
Missing Data and its Impact on Official AQI
The 125 station-hours of readings that were initially missing from CPCB records all showed PM2.5 levels above 1,000 µg/m³ on the DPCC website. An unnamed government official attributed the initial data gaps to “technical glitches.” When both sources had readings, the figures matched, indicating the DPCC data was consistent.
The absence of these critical readings impacted Delhi's official Air Quality Index (AQI). Although the AQI caps at 500, the extremely high PM2.5 numbers, once factored in, would have pushed the index higher. CPCB's own calculation method, incorporating the newly released data, estimates Delhi's AQI for the 24 hours to 9:00 AM on November 9 at approximately 384, higher than the 370 CPCB initially published. Similarly, the 4:00 PM bulletin's AQI would be around 360, compared to the 344 published.
The AQI index stops increasing once PM2.5 levels cross approximately 420 µg/m³, meaning readings in the thousands contribute little more to the overall AQI score beyond that point. As of the reporting on November 10, 2026, these revised figures had not yet appeared in CPCB's public records, and all figures remain provisional.