Air quality of Delhi slips to ‘very poor’ for first time this winter, Stage 2 of GRAP invoked

The “very poor” category signals seriously unhealthy air conditions. The Central Pollution Control Board says prolonged exposure at this level could lead to respiratory illness. AQI is a daily measure in which a higher number indicates worsening air quality.

Delhi’s 24-hour average AQI was 324 at 4 p.m. on November 2, 2026. The CPCB daily bulletin treated this reading as the day’s AQI. It was the first time this winter that Delhi entered the “very poor” category.

The Air Quality Early Warning System expected very poor air for the following three days. The last such reading had been recorded on February 11, when Delhi’s AQI was 305. The deterioration prompted CAQM to announce Stage 2 of GRAP, bringing additional pollution-control measures.

Delhi’s AQI worsened sharply between November 1 and November 2. It rose from 261, classified as “poor,” to 324, classified as “very poor.” The increase was 63 AQI points in just one day, or roughly 24% compared with the earlier reading.

The figures came from the CPCB’s daily bulletin. The bulletin records the 24-hour average AQI, and its 4 p.m. reading is treated as the day’s official AQI. A higher AQI indicates worsening air quality, so the rise represented a substantial deterioration.

The change mattered because Delhi crossed into a more polluted category for the first time this winter. The Air Quality Early Warning System predicted very poor conditions for three more days. In response, CAQM announced Stage 2 of GRAP on November 2.

Stage 2 of the Graded Response Action Plan is a package of short-term emergency measures for reducing air pollution. GRAP has four stages, and CAQM activates them according to pollution levels recorded or forecast for the near future. Stage 2 is therefore a response to worsening or persistently high pollution.

Under this stage, NCR State governments must enhance vehicle parking fees to discourage private-car use. The Delhi government and relevant NCR governments must also stagger timings for public offices and municipal bodies in Delhi, Gurugram, Faridabad, Ghaziabad, and Gautam Buddha Nagar.

The directions also include existing pollution-control measures. These include mechanical sweeping of roads and sprinkling water on roads. The aim is to reduce pollution sources and limit exposure while very poor air is expected to continue.

Stage 2 is designed to make private vehicle use less attractive and public transport more practical. NCR State governments must enhance parking fees. Delhi and the concerned NCR governments must stagger timings for public offices and municipal bodies, helping spread travel demand rather than concentrating it.

The affected areas include Delhi, Gurugram, Faridabad, Ghaziabad, and Gautam Buddha Nagar. The Delhi Metro Rail Corporation will also run 20 additional weekday trips. It had already been operating 20 extra trips since October 28, when GRAP Stage 1 was enforced.

DMRC said the additional service is intended to encourage public transport and help mitigate pollution. Together, the parking, scheduling, and Metro measures seek to reduce dependence on private vehicles while very poor air is forecast for the next three days.

Delhi-NCR’s air pollution usually worsens in winter because weather conditions make it harder for pollution to clear. The article identifies lower wind speeds and falling temperatures as the main meteorological factors behind the seasonal spike. These conditions affect Delhi-NCR and much of the wider Indo-Gangetic Plains.

During October and November, stubble burning adds pollution to the air. Firecrackers during the festive season add more. These sources combine with pollution already produced by vehicles and road dust, making overall air quality worse. The result can be a rapid rise in the AQI.

The pattern was visible on November 2, when Delhi’s AQI climbed to 324, or “very poor,” from 261 the previous day. The Early Warning System expected very poor air for three more days, leading CAQM to activate Stage 2 of GRAP.

The article identifies four important pollution sources: vehicles, road dust, stubble burning, and festive firecrackers. It does not specify the exact pollutants released by each source. In general terms, vehicle exhaust adds gases and fine particles, while disturbed road dust adds airborne dust particles.

Stubble burning and firecrackers are burning sources. Their smoke contains particles and gases, adding to pollution already present in the region. The key mechanism is cumulative: emissions from several sources enter the same air, while winter weather makes removal more difficult.

These sources helped worsen Delhi’s air during the seasonal pollution period. On November 2, the AQI reached 324, up from 261 a day earlier. CAQM responded with Stage 2 measures, including higher parking fees, staggered timings, road sweeping, and water sprinkling.

Wind normally helps move polluted air away from where it was produced. When wind speeds fall, pollutants remain over the same area for longer. Cooler temperatures can also limit vertical mixing near the ground, so pollution is less readily dispersed into the wider atmosphere. These mechanisms explain why winter weather can intensify pollution.

The article names lower wind speeds and falling temperatures as key meteorological factors behind pollution spikes. They do not create every emission, but they allow pollution from vehicles, dust, stubble burning, and firecrackers to remain concentrated and accumulate.

This seasonal pattern affects Delhi-NCR and many parts of the Indo-Gangetic Plains. Delhi’s AQI rose from 261 to 324 in one day as winter pollution worsened. The forecast expected very poor air for three days, prompting CAQM to announce Stage 2 of GRAP.