Delhi chokes as AQI crosses 460, ‘severe+’ air triggers emergency lockdown-like curbs

Delhi and the National Capital Region woke up on December 14 to a suffocating blanket of toxic smog and dense fog, as air quality deteriorated further into the hazardous zone, forcing authorities to invoke Stage-IV emergency measures under the Graded Response Action Plan (GRAP).

What was already a ‘severe’ pollution episode on December 13 worsened overnight, with a thick grey haze choking the capital, slashing visibility and pushing the air quality index (AQI) to alarming levels. Data from the Central Pollution Control Board (CPCB) showed Delhi’s average AQI rising to 461 at 7 am, up from 431 a day earlier, firmly placing the city in the ‘severe+’ category.

All monitoring stations breach severe levels

Every one of Delhi’s 40 air quality monitoring stations recorded ‘severe’ readings, several brushing dangerously close to the maximum measurable limit. Rohini topped the chart with an AQI of 499, followed by Bawana (498), Vivek Vihar (495), Ashok Vihar and Wazirpur (493 each), Narela (492) and Anand Vihar (491).

Pollution levels remained perilously high across other key locations as well, including Mundaka (486), ITO (485), Punjabi Bagh (478), Nehru Nagar (476), Chandni Chowk and Okhla (470 each). Even traditionally cleaner areas such as Lodhi Road (400) and Najafgarh (404) failed to escape the grip of toxic air.

NCR cities reel under pollution onslaught

The air quality emergency extended beyond Delhi, with several NCR cities recording equally distressing levels. Noida registered an AQI of 470, while Ghaziabad stood at 460, both in the ‘severe’ category. Gurugram’s air remained ‘very poor’ at 348, and Faridabad recorded a ‘poor’ 220, offering little comfort amid the regional crisis.

Dense fog worsens visibility, airport on alert

The pollution was visible from the early hours as dense smog mixed with fog engulfed large parts of the city, reducing visibility to near zero in some pockets. The deteriorating conditions disrupted early-morning movement and prompted authorities to activate low-visibility procedures at the Indira Gandhi International Airport.

While flight operations continued, officials said pilots were operating under enhanced precautionary protocols due to rapidly fluctuating visibility.

The India Meteorological Department (IMD) warned that visibility at the airport could drop to as low as 100 metres in dense fog during early morning hours, improving to around 800 metres later in the day. Moderate to dense fog is likely to persist across Delhi over the coming days.

Weak winds, western disturbance trap pollutants

According to the IMD, a feeble western disturbance over northwest India, coupled with a strong subtropical westerly jet stream, has led to weak or calm winds, a shift in wind direction and increased moisture in the lower atmosphere.

These conditions are ideal for the formation of smog and fog, effectively trapping pollutants close to the surface and preventing their dispersion — a key factor behind the sudden spike in AQI, authorities said.

Stage-IV GRAP enforced across NCR

Late Saturday night, the Sub-Committee of the Commission for Air Quality Management (CAQM) convened an emergency meeting and ordered the immediate implementation of Stage-IV of GRAP across the entire NCR, classifying the situation as ‘Severe+’.

The decision came as Delhi’s AQI climbed steadily through the evening, rising from 431 at 4 pm to 441 by 6 pm, signalling a sharp and sustained deterioration.

Emergency curbs: Trucks barred, construction halted

Under the five-point emergency action plan, BS-IV diesel trucks have been barred from entering Delhi, except those carrying essential commodities or services. Only LNG, CNG, electric and BS-VI diesel trucks are permitted.

Delhi-registered BS-IV and older diesel heavy goods vehicles have also been banned from plying, except for essential services.

All construction and demolition activities have been halted, including public infrastructure projects such as highways, flyovers, power transmission lines and pipelines. Stone crushers, mining operations and allied activities across the NCR have been ordered to shut down.

Schools move to hybrid mode

State governments across the NCR and the Delhi government have been directed to shift classes for Class VI to IX and Class XI to a hybrid mode, allowing a mix of physical and online learning. Authorities may extend the option to other classes and regions, with the choice of online attendance left to students and guardians.

Further measures — including college closures, restrictions on non-essential commercial activities and even odd-even vehicle norms — may be considered if conditions worsen.

Health advisory issued as risks mount

CAQM has urged residents to strictly follow the GRAP citizen charter. Children, the elderly and those with respiratory, cardiovascular or chronic illnesses have been advised to avoid outdoor exposure and remain indoors as far as possible, using masks if stepping out is unavoidable.

Brief respite fades as pollution tightens grip

The crisis marks a sharp reversal from earlier in the week, when Delhi’s AQI briefly dipped to 282 on December 9 and 259 on December 10. The respite proved fleeting, with pollution levels rising steadily from Thursday, breaching ‘severe’ levels on Saturday and worsening further on Sunday.

With toxic smog continuing to shroud the capital and weather conditions remaining unfavourable, authorities have warned that hazardous air quality may persist in the coming days, deepening health concerns and disrupting daily life across Delhi-NCR.