Pollution data unavailable amid technical glitches as haze envelopes Delhi

The problem has persisted since Sunday, when Delhi’s Air Quality Index (AQI) data was not updated for around 11 hours post-noon

Updated on: Oct 27, 2025, 11:21:38 IST

By Jasjeev Gandhiok

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Technical glitches in updating pollution data continued as Delhi’s Air Quality Index (AQI) remained stuck on 315 (very poor), and a haze enveloped the city on Monday. The Central Pollution Control Board’s (CPCB) Sameer app showed the last update for AQI data was at 10:43pm. There have been no updates since.

The previous forecasts showed the AQI was likely to stay “very poor” on Monday. (HT PHOTO)

Updated AQI data was also missing from the CPCB website, which officials said was due to a technical glitch. The problem has persisted since Sunday, when AQI data was not updated for around 11 hours post-noon. The CPCB failed to release its daily national bulletin at 4pm, which was eventually issued at 10:45pm.

The bulletin showed Delhi’s AQI was 315, a deterioration from 292 (poor) on Saturday. “There were some technical glitches. Old data from some stations had flooded our servers and had to be manually fixed,” an official said.

The Sameer app at 10:43pm showed that out of the 38 active stations, Anand Vihar (431) and Bawana (401) were in “severe” and 23 were in “very poor” categories at that time. It usually shares an updated 24-hour AQI every hour, meaning data has not been updated for at least 12 hours now.

An AQI of 51 to 100 is classified as “satisfactory”, 101 and 200 as “moderate”, 201 and 300 as “poor”, 301 and 400 as “very poor”, and over 400 as “severe”, as per the CPCB.

Hourly readings for all eight pollutants used to calculate the AQI — including PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb — were available on the Delhi Pollution Control Committee (DPCC)’s website, indicating that data were still being gathered.

On January 1, data for AQI stations across Delhi-NCR were unavailable due to a similar server issue. On November 14, 2023, data were available for nine out of the 40 stations for hours. DPCC‘s stations were unable to share or transmit data to the CPCB.

On October 31, 2022, data was not updated for over 11 hours due to a similar glitch. Data on CPCB’s app remained stuck between 5am and 4pm. The national bulletin was released for that day.

The previous forecasts showed the AQI was likely to stay “very poor” on Monday, before possibly improving again as wind speed may marginally increase.

ABOUT THE AUTHOR
Jasjeev Gandhiok
Jasjeev Gandhiok is an Assistant Editor with Hindustan Times, where he covers environment, climate change, the clean energy transition and wildlife at the National Bureau. Gandhiok has over a decade of experience in journalism and is based in Delhi. He has reported extensively on Delhi and the National Capital Region (NCR). This includes the region's air pollution woes, a polluted Yamuna and on urban wildlife still thriving in the region. He joined HT in October 2021. Prior to that, he had five-year stint at The Times of India in Delhi, where he also covered Delhi, with a focus on environment and wildlife. Gandhiok has covered some recent events around the Capital too, ranging from the farmers' protests, the northeast Delhi riots and the CAA-NRC protests, reporting from the ground on all of these. He also travels across the country to report on how environment and climate change impact everyday life, while also writing on endangered species. His reports in 2019 on toxic leachate from Delhi's landfills led to the National Green Tribunal (NGT) taking suo motu cognisance and ultimately asking the state government to start bio-mining to flatten and remove all three landfills in the capital. He also closely tracks the implementation of government policies on climate, renewable energy and environmental protection. His focus remains on impactful, public-interest journalism which explains how environmental decisions affect people's everyday lives.Read More

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