Delhi's air monitoring stations missed key pollution data during Diwali's toxic air spike.

On Diwali night, Gurgaon’s PM2.5 levels soared to 16 times the national limit as residents continued bursting crackers well past the Supreme Court’s permitted 8–10 pm window. The hourly concentration of PM2.5—a fine particulate pollutant linked to respiratory problems—rose sharply, with Sector 51 recording the highest at 949 micrograms per cubic metre around midnight. Despite restrictions, fireworks continued sporadically till 2 am in several neighbourhoods, including DLF phases, Sector 56, Palam Vihar, and Golf Course Extension. Residents complained that noise and smoke lingered for hours, reducing visibility. Officials said the city’s air quality remained in the ‘severe’ category for several days after Diwali.

If rationality and data take a backseat, the courts hesitate to take reasonable decisions, and a government which must prioritise public health does the opposite, then democracy – which is about accountability to the people and the well-being of all – also suffers.

Vaani Kapoor is currently in Delhi to celebrate Diwali with her family. The actress on Tuesday took to Instagram to share that she woke up to Delhi's AQI touching 447, and she has urged people to celebrate the festival without dimming the air quality. Read on to know more...

It was a noisy Diwali in Delhi as ‘green’ fireworks burst non-stop across the capital. Now it sits under a thick, choking blanket of smog filled with ultra-fine pollutants. According to data, the average AQI touched the ‘severe’ category, at 451, at 7 am on Tuesday, 1.8x above the national average

The transport sector contributes the most to the national capital’s toxic air but is consistently overlooked when it comes to policy discussions and actions.

Gurgaon is expected to witness dense haze following Diwali as weather conditions turn unfavourable for pollutant dispersion. According to the IMD, wind speeds will drop below 8 kmph, and calm conditions may trap smoke, causing AQI levels to deteriorate sharply after the festival.

रोहतक में दिवाली से पहले वायु गुणवत्ता सूचकांक (एक्यूआई) बढ़कर 290 तक पहुंच गया है, जिससे हवा 'बहुत खराब' श्रेणी में आ गई है। प्रशासन ने ग्रेप-2 के नियम लागू करते हुए सड़कों पर पानी का छिड़काव और सफाई अभियान शुरू किया है।

The deteri­or­a­tion in Delhi’s air qual­ity, which was skirt­ing the “very poor” cat­egory on Sunday, was caused more by external factors than from sources within the cap­ital, accord­ing to the Centre’s Decision Sup­port Sys­tem (DSS). Data on Sunday showed at least 67.89% of Delhi’s total PM2.5 con­tri­bu­tion was from external sources.

The deterioration in Delhi’s air quality, which was skirting the ‘very poor’ category on Sunday, was caused more by external factors than by sources within the capital, according to the Centre’s Decision Support System (DSS).
Data on Sunday showed that at least 67.89% of Delhi’s total PM2.5 contribution was from external sources.
For the sources within Delhi, the transport sector in Delhi accounted for 16.43% of the pollution in the city, followed by Delhi’s residential sector (4.27%) and then the industries sector (3.63%).

Studies have previously shown that the city’s particulate matter levels spike sharply in the days leading up to and during Diwali

City’s pollution worsens even before the festival, with Anand Vihar’s AQI hitting 384 (“very poor”) and several areas crossing 200

Ground-level ozone has been the lead pollutant on 10 of the 17 days this October, according to the Central Pollution Control Board (CPCB). While October normally sees the highest ozone levels, this year’s concentration exceeded 90 micrograms per cubic metre on several days, making it the highest for October since 2020.

The pollution build-up in Noida has been peaking between 7 pm and midnight — a pattern distinct from Delhi where spikes tend to occur later at night.

The top eight most polluted cities in India were all in NCR, painting a grim picture of what lies ahead in coming weeks as temperature drops in the region.

In 2024, the Supreme Court had said, “If firecrackers are burst in this fashion, it affects the fundamental right to health of citizens.” 

Experts say many of Delhi’s air quality monitoring stations may give inaccurate readings, because they are not placed properly — for example, too close to trees or buildings, or near roads.

These faults make it hard to trust whether the reported pollution levels reflect real “clean air” conditions.

The Supreme Court’s order to allow green crackers on a “test basis” just days before Diwali has reopened debate over balancing tradition and health.

Experts say there is no clear way to check whether a cracker is truly green, and past attempts at enforcement have been weak.

The Commission for Air Quality Management (CAQM) is currently operating with a 35 per cent staff shortage, while state bodies like the Delhi Pollution Control Committee (DPCC) and the Uttar Pradesh Pollution Control Board (UPPCB) also suffer from similar constraints.

Experts warn that giving short notice for new guidelines will make it very hard to enforce them properly in Delhi. The lack of time, resources, and coordination could mean many people ignore the rules.