Why city’s ‘moderate’ AQI doesn’t clear the air on what you’re breathing: 2 Of 4 recording stations offline for days in peak pollution season

GURGAON: If you step outside and breathe in what feels like a smoky haze, you are not imagining things — despite the AQI reading showing ‘moderate’.

The city’s air quality has stayed at 177 for two days on the trot — a comforting surprise for this part of the year when farm fires peak and windspeeds slow down. Yet, this number tells only part of the story — and perhaps not the most important part. With two of the city four air monitoring stations offline for days, the figures offer an illusion, rather than an accurate reflection of what residents are actually inhaling.


Currently, only the Vikas Sadan and Gwal Pahari stations are operational, recording AQI levels of 150 and 206, respectively. The Teri Gram monitor has been out of action for almost six months, while the Sector 51 station — which has just resumed after a week-long blackout — had consistently reported “very poor” air quality before it went dark. As a result, the city’s overall AQI is being calculated from a patchy and unrepresentative data set, failing to capture the full scale of pollution across the city.

At the Sector 51 station on Tuesday, TOI found the display screen blank.

Officials from Haryana State Pollution Control Board (HSPCB) cited technical glitches. “We have informed Central Pollution Control Board. We are able to collect data, but it’s just not getting uploaded,” said an HSPCB official.

Experts warned that such data gaps not only distorted the pollution picture but also eroded public trust.

“When half the monitors are down, the AQI number loses credibility. No prizes for guessing that pollution levels near industrial areas, arterial roads, and construction sites would be significantly higher than what is being reported,” said Shubhansh Tiwari, a research associate at Centre for Science and Environment.

The timing could hardly be worse. As the annual smog season deepens across NCR — driven by crop residue burning and temperature inversions — accurate real-time data is crucial for both public health and regulatory action like Graded Response Action Plan.

Yet, at the very moment when vigilance is most needed, the city’s already limited monitoring system is faltering, experts pointed out.

“Gurgaon, anyway, is insufficiently monitored according to CPCB criteria. We cannot afford blank readings during peak pollution episodes. The sensors must be upgraded or replaced so the true severity of air pollution isn’t hidden behind ‘no data’ screens,” said Manoj Kumar, analyst at the Centre for Research on Energy and Clean Air.

The issue goes beyond technical failures and raises the question of accountability. “When residential area stations that consistently report very poor air go offline for days, it’s not just a technical glitch. It’s a governance failure. The unavailability of real-time data deprives citizens of their right to know what they’re breathing. It also shows a worrying lack of preparedness of agencies responsible for maintaining continuous air quality surveillance,” said Arun Kumar Yadav, clean air programme manager at Envirocatalysts.

A similar experience by Delhi during the Diwali days offers a caution.

An analysis by TOI revealed that during the critical hours of Oct 20 and 21 — when pollution typically peaks — only 12 of 39 air-quality stations in the capital recorded uninterrupted hourly data. Across the network, there were 173 missing hours of data, with about 163 of those during the overnight peak, when air quality was likely at its worst. This means the official AQI for Delhi during Diwali (310–350) almost certainly underestimated actual exposure, leaving both regulators and the public blind during the most hazardous period.

Since Diwali, Gurgaon’s air has remained polluted, with levels fluctuating between ‘poor’ and ‘very poor’ even as the official numbers suggest improvement. With farm fires in neighbouring states now peaking and winter conditions setting in, experts warned that AQI levels were likely to worsen in the coming days.