In response to the severe drop in air quality in Delhi on Saturday evening (December 13, 2025), the Commission for Air Quality Management in NCR and Adjoining Areas (CAQM) implemented stage 4 of the Graded Response Action Plan (GRAP), a series of emergency measures to limit air pollution.
The Air Quality Index (AQI) was 441 as of 6 p.m. on Saturday (December 13). Earlier in the day, the CAQM applied limitations as part of the third stage of anti-pollution efforts.
Saturday (December 13) was the worst air quality of the year so far, topping the previous high of 428 set on November 11, according to government statistics. Slow wind speed, adverse weather parameters, and climatic circumstances have all contributed to the decline in air quality.
“Keeping in mind the current trend of air quality and in an effort to prevent further deterioration of air quality in the region, the CAQM Sub-Committee on GRAP decides to invoke all actions as envisaged under Stage-IV of the existing GRAP – ‘Severe+’ Air Quality (DELHI AQI > 450), with immediate effect, in the entire NCR,” the CAQM said in a statement.
GRAP-IV restrictions are in addition to the activities taken under Stages I, II, and III of the existing GRAP, which are currently in place across the NCR, according to the CAQM. When the AQI exceeds 450, Stage 4 takes effect.
The Air Quality Early Warning System anticipated that the AQI will stay “severe” on Sunday (December 14). GRAP-IV in Delhi-NCR: What is permitted and what is prohibited as AQI increases to “severe plus”
Stage 4 limits include a prohibition on all building operations, the admission of non-essential polluting vehicles into Delhi, and the required conversion of school courses, with the exception of classes 10 and 12, to hybrid mode.
Non-essential diesel trucks are restricted from entering Delhi, as are Delhi-registered BS-IV and earlier diesel-powered heavy goods vehicles, with the exception of necessary services under Stage 4.
According to the Central Pollution Control Board (CPCB), an AQI of 0 to 50 is considered “excellent,” 51 to 100 “acceptable,” 101 to 200 “moderate,” 201 to 300 “poor,” 301 to 400 “extremely poor,” and 401 to 500 “severe.”
