Delhi woke up on Saturday to a dense layer of haze and persistent toxic smog, with the city’s overall Air Quality Index (AQI) registering at 335 in the ‘very poor’ category, according to the Air Quality Early Warning System. As winter begins to settle in, pollutant accumulation has intensified across the capital, dragging Delhi deeper into the season’s familiar air quality crisis. Several neighbourhoods reported hazardous levels, with some areas breaching into the ‘severe’ zone as particulate matter became trapped close to the surface.

The deterioration follows Friday’s already alarming 24-hour average AQI of 322, which placed Delhi in the ‘red zone’ and made it the most polluted major urban centre in the country, according to data from the Central Pollution Control Board (CPCB). The onset of winter, low wind speed, vehicular emissions, construction dust, and increasing farm fires in neighbouring states have collectively worsened the city’s air quality.

Worst-hit pockets: Bawana, Vivek Vihar and Wazirpur

CPCB readings at 8:00 am on Saturday highlight sharp variations across neighbourhoods, though most localities recorded uniformly poor conditions. Bawana was the most polluted in the city with an AQI of 403, officially entering the ‘severe’ category. This level of pollution is capable of causing respiratory distress even in healthy individuals and poses a serious threat to vulnerable groups.

Vivek Vihar followed closely with an AQI of 387, hovering near the severe threshold. Wazirpur reported an AQI of 381. These regions, located in industrial and densely populated belts, frequently register high levels of PM2.5 during the winter months due to trapped emissions and localised pollution sources.

Several other areas, including Mundka (375), Punjabi Bagh (375), Burari Crossing (374), and ITO (373), also reported dangerous air. These neighbourhoods experience heavy traffic, industrial activity and elevated construction dust, compounding their pollution burden. Areas such as Jahangirpuri (365), Sonia Vihar (365), and Ashok Vihar (360) remained firmly in the ‘very poor’ category.

In total, more than twenty monitoring stations across Delhi reported AQI levels above 330, leaving little respite for residents anywhere in the city.

Area-wise AQI snapshot as of 8 am

Data from the CPCB shows the extent of pollution spread across Delhi:

• Bawana: 403 (Severe)
• Vivek Vihar: 387 (Very Poor, bordering Severe)
• Wazirpur: 381 (Very Poor)
• Mundka: 375 (Very Poor)
• Punjabi Bagh: 375 (Very Poor)
• Burari Crossing: 374 (Very Poor)
• ITO: 373 (Very Poor)
• Jahangirpuri: 365 (Very Poor)
• Sonia Vihar: 365 (Very Poor)
• Rohini: 361 (Very Poor)
• Ashok Vihar: 360 (Very Poor)
• Pusa, Delhi: 359 (Very Poor)
• CRRI Mathura Road: 359 (Very Poor)
• Narela: 358 (Very Poor)
• Anand Vihar: 356 (Very Poor)
• Alipur: 353 (Very Poor)
• Patparganj: 352 (Very Poor)
• Chandni Chowk: 352 (Very Poor)
• North Campus, DU: 347 (Very Poor)
• Sirifort: 343 (Very Poor)
• Mandir Marg: 342 (Very Poor)
• Dr. Karni Singh Shooting Range: 339 (Very Poor)
• Okhla Phase-2: 338 (Very Poor)
• RK Puram: 337 (Very Poor)
• Dwarka Sector-8: 318 (Very Poor)
• Jawaharlal Nehru Stadium: 322 (Very Poor)
• Major Dhyan Chand National Stadium: 322 (Very Poor)
• Sri Aurobindo Marg: 301 (Very Poor)
• Shadipur: 299 (Poor)
• DTU: 291 (Poor)
• Najafgarh: 286 (Poor)
• Aya Nagar: 281 (Poor)
• IGI Airport T3: 271 (Poor)
• IHBAS, Dilshad Garden: 224 (Poor)
• Lodhi Road: 235 (Poor)
• NSIT Dwarka: 211 (Poor)

The CPCB categorises AQI levels as: 0–50 (Good), 51–100 (Satisfactory), 101–200 (Moderate), 201–300 (Poor), 301–400 (Very Poor), and 401–500 (Severe). Every locality in Delhi remains above the ‘moderate’ level, revealing the scale of the pollution crisis.

Reason for sustained ‘very poor’ air: PM2.5 remains the main pollutant

The Decision Support System (DSS) for air quality forecasting indicated that PM2.5 continues to be the dominant pollutant in Delhi’s atmosphere. The tiny particulate matter is particularly harmful because it penetrates deep into the lungs and enters the bloodstream.

According to DSS data, stubble burning accounted for 8.6 percent of Delhi’s overall pollution load on Friday. However, this contribution is expected to rise sharply as farm fire incidents increase across Punjab, Haryana, and parts of Uttar Pradesh. DSS forecasts predict that stubble burning could contribute 30.9 percent of Delhi’s pollution on Saturday and 31.2 percent on Sunday.

Satellite observations reinforce this trend. On Thursday, Punjab recorded 351 farm fire incidents, Haryana reported 35, and Uttar Pradesh documented 200 cases. These numbers typically rise in the first half of November as farmers clear crop residue before winter crop sowing.

Local sources also worsen Delhi’s air

While stubble burning receives significant attention, local emissions are equally responsible for deteriorating air quality. DSS estimates that the transport sector will contribute 15 percent of PM2.5 on Saturday and 14 percent on Sunday. Increasing vehicular movement, construction dust, industrial emissions, and household pollution further intensify the problem.

Low wind speeds and temperature inversion during early winter trap pollutants close to the ground, preventing dispersion. Without rain or strong winds, Delhi’s air tends to stagnate, causing daily AQI values to remain elevated.

Very poor air expected to persist

Forecasts from the Air Quality Early Warning System indicate that the capital’s AQI will remain in the ‘very poor’ category for the next several days. Meteorological conditions including low wind, hazy mornings, and falling temperatures show little sign of improving in the immediate term.

The air quality trend has been worsening steadily since Diwali, with many localities touching or crossing into the ‘severe’ category intermittently. The lack of significant atmospheric changes suggests that residents may face sustained exposure to unhealthy air.

Effects on public health and daily life

Extended periods of very poor or severe air quality pose multiple health risks. Exposure to PM2.5 can trigger respiratory issues, aggravate asthma, reduce lung function and lead to cardiovascular complications. The elderly, children, outdoor workers and those with pre-existing conditions are especially vulnerable.

In recent years, healthcare institutions in Delhi have reported spikes in respiratory complaints during November, often coinciding with farm fire peaks and winter smog accumulation. Residents are increasingly advised to avoid outdoor activity during the early morning and evening hours, use air purifiers indoors and limit strenuous physical activity.

Schools and offices frequently modify schedules, and outdoor sports activities become challenging as smog intensifies. For many parts of the city, daily life adapts to the seasonal air quality crisis.

Looking ahead

Delhi’s persistent pollution problem reflects a complex mix of external and internal factors. While stubble burning remains a notable seasonal contributor, the city’s chronic emissions—from transportation, construction and industry—continue year-round. The winter atmosphere acts as a lid, amplifying the impact of all sources simultaneously.

With pollution levels expected to remain high in the coming days, authorities may announce additional restrictions on construction activities, diesel generator use, and vehicular movement if conditions worsen further.

If you want, I can also prepare a short 10-point summary, a neighbourhood-wise risk assessment, or a simplified explainer on PM2.5 for general readers.