No end to bad air ordeal: AQI back in severe zone in Delhi
The Commission for Air Quality Management has invoked the third stage of the Graded Response Action Plan, banning certain vehicles and private constructions.
Authorities brought back curbs on some older private cars and ordered private constructions works to halt as the air pollution shot up to the “severe” zone for the first time since November 24 on Friday, plunging the city into a painfully familiar haze.

Delhi’s 24-hour average air quality index (AQI) was recorded at 409 (severe) according to the Central Pollution Control Board’s national bulletin at 4pm, deteriorating sharply from was 361 (very poor) a day earlier and 285 (poor) on Wednesday.
Read here: Delhi-NCR AQI: Non-essential construction work banned, curbs imposed on vehicles
Officials said at fault was a change in meteorological conditions marked by weak winds, which trapped local emissions from construction work, vehicle exhaust gases, and smoke from bonfires and garbage burning.
Friday’s spike in pollution marks the return of what has been a particularly bad last two months for the Capital’s air quality.
The Capital lived through its third most polluted November this year, with the average AQI at 373. In fact, save for some outlier days when rain helped bring pollution levels down, the average AQI in November comes close to 390, making it the most polluted ever.
So far, in December, the average AQI is 330, the third worst since 2016. Delhi’s average AQI for the December is the second worst since 2018, when it was 339, not much different from this year. This December, in fact, began on a cleaner note — the average AQI was better than past averages up to December 11. But from December 12, the air quality began plummeting to levels worse than past averages.
The Commission for Air Quality Management (CAQM) held an emergency meeting on Thursday and decided to invoke the third stage of the Graded Response Action Plan (Grap) with immediate effect, banning BS-III petrol and BS-IV diesel private cars from being used in the Delhi-NCR region. The restrictions also apply to private constructions.
“Unfavourable meteorology including fog and hazy conditions, along with low wind speed are the major causes for sudden spike in Delhi’s daily average AQI. Keeping in view the prevailing trend of air quality, and in an effort to prevent further deterioration of air quality in the region, the CAQM subcommittee has taken the call to reinvoke all actions as envisaged under Stage-3 of GRAP’s — “severe” air quality (AQI ranging between 401-450) category, with immediate effect in the entire NCR,” CAQM said in a statement on Friday.
There is little evidence, however, that these measures can stem or alleviate the worsening of air quality once pollution levels have already spiked. The ban on BS-III and BS-IV petrol and diesel vehicles covers around 387,000 vehicles registered in Delhi, a fraction of the seven million registered in total.
The AQI is predicted to remain “severe” on Saturday too, before possibly improving to “very poor” on Sunday, according to the Early Warning System (EWS) for Delhi, a forecasting model under the ministry of earth sciences.
Dipankar Saha, former head of CPCB’s air laboratory, said calm wind conditions are fairly common towards the end of December and early January, when temperatures start to dip. “Low temperatures make the atmosphere stable, leading to calm winds, which do not allow pollutants to disperse. An approaching western disturbance can also have the same effect,” he said.
The India Meteorological Department (IMD), meanwhile, said there were chances of a drizzle in isolated parts of NCR late on Friday night, and issued a yellow alert for dense fog on Saturday morning.
“The lowest visibility in Delhi on Friday was 300 metres and with a western disturbance approaching, more moisture will be added into the atmosphere. Visibility may go below 200 metres on Saturday morning,” said Kuldeep Srivastava, scientist at IMD.
Stage-3 measures were invoked for the first time this season on November 2, when Delhi recorded its first “severe” air day of the winter. They were lifted on November 29, when the AQI improved to under 300 following light rain across the city.
Read here: Delhi-NCR residents take note: These vehicles are banned due to high AQI
Across NCR, the AQI in the neighbouring towns was recorded in the “poor” to “very poor” category, CPCB data showed. Greater Noida had an AQI of 386 (very poor), Noida and Ghaziabad 376 each (very poor), Gurugram 314 (very poor), and Faridabad 282 (poor).
(With inputs from Abhishek Jha)
