At peak of air pollution on Deepavali night, data goes missing at several govt monitoring stations in Delhi
Delhi air quality data vanished at peak Deepavali pollution, potentially masking worse AQI across multiple monitoring stations.
“When the hourly PM2.5 data is missing, it will artificially lower the Air Quality Index (AQI), showing better air quality, when the actual air quality is worse,” Manoj Kumar, analyst, Centre for Research on Energy and Clean Air (CREA) said
Updated - November 09, 2026 05:54 pm IST - New Delhi
People commute shrouded in thick smog during early morning hours after Deepavali night in New Delhi on November 09, 2026. | Photo Credit: Shashi Shekhar Kashyap
At the peak of pollution, following the bursting of firecrackers on Deepavali night, air quality data was missing from several monitoring stations managed by government authorities, raising questions over the actual air pollution levels.
Air quality readings went blank for several stations for many hours, as per websites of the Delhi government’s Delhi Pollution Control Committee (DPCC) and the Central government’s Central Pollution Control Board (CPCB).
Data of PM2.5 was missing for several hours for many stations in Delhi including Anand Vihar, Patparganj, Bawana, among others, as per DPCC’s website.
PM2.5 (Particulate matter 2.5) are fine inhalable particles, which can get into lungs and bloodstream and lead to a range of respiratory and other diseases.
Last year also, data went missing from many stations in a similar way during Deepavali.
DPCC data for Anand Vihar.
‘Show better air quality’
Manoj Kumar, analyst, Centre for Research on Energy and Clean Air (CREA), a Finland-based non-profit research organisation, said that missing hourly PM2.5 data “raises concerns” over Delhi’s air quality assessment.
“Since midnight on November 8 until 5 a.m. on November 9, 227 hourly PM2.5 observations were missing across 59 CPCB monitoring stations in Delhi. Only 14 stations reported complete data, while the remaining 45 had at least one missing hourly observation,” Mr. Kumar said.
“When the hourly PM2.5 data is missing, it will artificially lower the Air Quality Index (AQI), showing better air quality, when the actual air quality is worse,” he added.
When asked about air quality data in Delhi missing in several monitoring stations, Delhi Labour Minister Kapil Mishra told the media that the government will look into the issue within an hour and inform the media about it.
DPCC data for Patparganj.
Pollution 173 times WHO limit
Before the data went missing for two hours, the level of PM2.5 (a major pollutant) in Patparganj was 2,597 micrograms per cubic metre at 1 a.m. on Monday (November 9, 2026) - about 173.13 times the WHO permissible limit - of 15 micrograms per cubic metre for a 24-hour period.
Similarly, after data went missing for three hours, the level of PM2.5 in Anand Vihar was 1,396 micrograms per cubic metre at 3 a.m. on Monday — about 93.06 times the WHO permissible limit.
Meanwhile, in the CPCB website, the data for PM2.5 seemed to be capped at 1,000 micrograms per cubic metre, showing more gaps in data than the DPCC website.
Mr. Kumar said that Siri Fort recorded 1,000 µg/m³, the maximum PM2.5 concentration displayed on the CPCB-CCR public portal.
“The portal does not display readings above this level, raising concerns about the representation of extreme pollution concentrations,” he said.
Mr. Kumar said that Siri Fort recorded 1,000 µg/m³, the maximum PM2.5 concentration displayed on the CPCB-CCR public portal.
“The portal does not display readings above this level, raising concerns about the representation of extreme pollution concentrations,” he said.
Meanwhile, both the AAP and the Congress attacked the BJP government over the missing data, with the former alleging that it was “data fraud”. Hitting back, Mr. Mishra alleged that there was a “conspiracy” by AAP-governed Punjab to set stubble on fire in Punjab on Sunday (November 8, 2026) evening.
Published - November 09, 2026 05:19 pm IST
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