Stage IV is invoked when the Air Quality Index (AQI) reaches “severe+” levels — above 450 — and triggers the most stringent restrictions, such as limits on vehicles, construction, industrial activity and school operations. CAQM’s sub‑committee decided to revoke its December 13 order that activated Stage IV, noting that the AQI had improved enough to justify easing the toughest curbs. The Times of India
Relief for Commuters and Businesses
With the lifting of Stage IV:
- BS‑IV petrol cars from outside Delhi are now permitted to enter the city, a ban that was part of the strictest controls. Hindustan Times
- Some of the most restrictive movement and activity bans have been rolled back. The Tribune
However, officials and experts warn that this relief may be short‑lived — air quality can fluctuate rapidly in winter due to weather and emissions patterns. The Times of India
Lower‑Stage Measures Still in Force
CAQM clarified that GRAP Stages I, II and III restrictions remain in effect and will continue to be enforced as per the modified GRAP framework notified in November 2025. These include measures on dust control, restrictions on older vehicles, and monitoring of industrial emissions aimed at preventing the air from deteriorating again. The Times of India
Authorities are keeping a close watch on meteorological conditions and AQI trends to decide if and when stricter curbs may need to be reimposed. Residents have also been urged to follow pollution‑reduction guidelines, especially in the winter when stagnant air can trap pollutants. Web India 123 News
Ongoing Air‑Quality Challenges
Although the Stage IV curbs are lifted, much of Delhi and the NCR continues to record “very poor” air quality levels, underlining the persistent pollution challenge in the region and the need for broader long‑term mitigation measures. The Times of India