Delhi marks second-longest streak of ‘very poor’ air days amid pollution woes

At 4pm, when the CPCB releases its daily national bulletin, the Capital’s average AQI registered at 369. The current streak began on November 6.

Delhi’s air quality index (AQI) remained above 300 for the 23rd consecutive day, the second-longest spell of ‘very poor’ or worse air days since 2019, according to Central Pollution Control Board (CPCB) data.

Delhi’s air quality index (AQI) remained above 300 for the 23rd consecutive day (HT photo)

At 4pm, when the CPCB releases its daily national bulletin, the Capital’s average AQI registered at 369. The current streak began on November 6, and has included three days of “severe” air between November 11 and 13.

The longest streak came last year, when Delhi logged 32 consecutive days of ‘very poor’ or worse air between October 30 and November 30, including a peak of 494 (severe) on November 18.

The CPCB classifies air as ‘good’ when AQI is 50 or lower; ‘satisfactory’ between 51 and 100; ‘moderate’ between 101 and 200; ‘poor’ between 201 and 300; ‘very poor’ between 301 and 400; and ‘severe’ when it exceeds 400.

Officials said the prolonged run this year is being driven by a combination of stagnant winds and falling temperatures. Forecasts by the Air Quality Early Warning System (AQEWS) indicate that the situation is unlikely to improve in the next six days, with wind speeds expected to remain low.

Despite this, the Commission for Air Quality Management (CAQM) this week rolled back measures under Stage 3 of the Graded Response Action Plan (GRAP), allowing an end to the ‘Work from Home’ mandate and hybrid classes for classes 5 and lower, as well as the resumption of construction activities.

Experts say that the prolonged streak exposes systemic failures in pollution control.

‘Tackle local emissions round the year’

Calling it a “public health emergency”, a Centre for Science and Environment (CSE) report warned that residents are breathing toxic pollution through the year, not just during the peak season. Its latest ‘Agenda for Action for Delhi-NCR’, released on November 27, said transport alone contributes 39%, the maximum, to Delhi’s PM2.5 load, with industry and construction making up 20%, and road dust accounting for 18%.

Even during peak farm-fire periods in November 2024, stubble burning contributed up to 25%, but local sources still dominated. The report further noted that nitrogen oxides (NOx)spike more than 2.3 times during evening congestion, when average traffic speeds drop to 15 km/h— worsening exposure at the neighbourhood level.

To break this cycle, CSE has recommended a seven-point agenda, including time-bound scrappage of old commercial fleets, faster electrification of vehicles, strict industrial fuel transition to natural gas, large-scale crop-residue management, stronger public transport, curbs on private car use and a complete ban on waste burning with reliable waste-segregation systems.

Most polluted among major cities

Meanwhile, Delhi has continued to top the list of India’s most polluted cities over the last decade, a fresh air-quality assessment by Climate Trends showed on Friday. The study, which analysed daily AQI data from 2015 to November 2025 across major urban centres, showed that the Capital has recorded the highest pollution levels almost every year, peaking above 250 in 2016.

Even with minor improvements post-2020, Delhi’s 2025 AQI still hovers around 180, the lowest yet, but still far from the safe threshold. Researchers attributed the city’s chronic poor air to dense traffic, industrial emissions, winter inversion and crop-burning impacts across the Indo-Gangetic plains. Geography also plays a key role, with the Himalayas trapping pollutants over the region during winter, experts said.