Delhi recorded its lowest average air quality index (AQI) for the first half of November in three years, even though pollution levels remained firmly in the “very poor” category. Between November 1 and 15, the city’s mean AQI stood at 348, an improvement compared to 367 in 2024 and 376 in 2023.
As per a TOI report, officials attribute the marginal relief to a combination of factors, an early Diwali this year, fewer stubble-burning incidents, favourable weather conditions and the frequent use of water sprinklers around pollution monitoring stations.
A Look At Delhi AQI
Historically, this two-week period is considered Delhi’s most polluted stretch. A Delhi Pollution Control Committee (DPCC) review of 2018–2023 data shows the average AQI for these dates typically hovers around 371, driven by spikes in farm fires, festive traffic and stagnant winter air.
However, experts warned against reading too much into this year’s numbers. Sunil Dahiya, founder of EnviroCatalysts, said irregularities such as water being sprayed near monitoring systems and obstructions affecting sensors could be skewing the AQI. He added that the annual surge in stubble burning also appeared later than usual this year.
Data from the Central Pollution Control Board shows three ‘severe’ days, 10 ‘very poor’ days, and two ‘poor’ days during this period. Last year, Delhi saw two severe days and 13 very poor days.
Another Spell Of Severe Pollution
Forecasts by the Air Quality Early Warning System suggest another spell of severe pollution is likely from Monday to Wednesday, with air remaining in the “severe” or “very poor” zone for the next several days.
Meteorologists say wind speed played a significant role in dispersing pollutants this year. Dipankar Saha, former head of CPCB’s air lab, noted that stronger winds have helped dilute emissions, and conditions could improve further if wind flow increases. DPCC data also indicates that Delhi’s second-worst pollution phase typically falls between December 15–31 (average AQI: 354) due to dense fog and heavy traffic during the wedding and holiday season. The third-most polluted period is January 1–15, with an average AQI of 324.