Delhi's air quality slipped into the "poor" category for the first time this season on October 21, with the air quality index (AQI) reaching 245, a 100-day high. The Commission for Air Quality Management (CAQM) invoked Stage I of the Graded Response Action Plan (GRAP) across Delhi and the National Capital Region.

Data from the Centre for Research on Energy and Clean Air shows that between 2015 and 2025, Delhi usually entered the "poor" band in the first half of October, making this year's date the latest in that period.

What Stage I means

  • Stricter dust control at construction sites and a ban on open burning of garbage and biomass.
  • Checks on Pollution Under Control (PUC) certificates and action against visibly polluting and overage vehicles.
  • Inter-state buses from Haryana, Uttar Pradesh and Rajasthan barred from Delhi-NCR unless electric, CNG or BS-VI diesel.
  • Mechanised road sweeping, water sprinkling and fire prevention at landfills.

Where the pollution comes from

According to the IITM decision support system, transport was the largest local contributor at 20.5%, and stubble burning about 8%, forecast to rise above 13%. Environment Minister Manjinder Singh Sirsa said the city had recorded about 214 clean-air days so far this year.

From November 1

Delhi will enforce a "No PUC, No Fuel" rule at fuel stations and restrict non-BS-VI vehicles registered outside Delhi (CNG and electric vehicles exempt). The government also plans 50% work from home for offices, staggered office timings and doubled parking charges until February 28; Delhi Metro parking is exempt.