Overview
- After invoking Stage 3 on January 16, the CAQM escalated to Stage 4 on January 17 as Delhi’s AQI jumped from 400 at 4 pm to 428 by 8 pm, later touching 434.
- Stage 4 suspends all construction and demolition and restricts most truck entry, allowing only essential loads and CNG/LNG, electric or BS‑VI vehicles.
- Stage 3 measures remain in force, including bans on BS‑III petrol and BS‑IV diesel four‑wheelers in Delhi, Gurugram, Faridabad, Ghaziabad and Gautam Buddh Nagar, and shutdowns of stone crushers and other high‑dust operations.
- Schools move to hybrid learning for younger grades, with authorities empowered to broaden curbs on in‑person classes and other non‑essential activities as needed.
- Pollution control boards were directed to intensify enforcement; dense fog kept low‑visibility procedures active at Delhi airport with delays reported, PM2.5 dominated readings, and forecasts point to severe air through Sunday before likely easing.