CAQM invokes GRAP Stage IV across Delhi-NCR as AQI crosses 400
The Commission for Air Quality Management (CAQM) invoked Stage IV of GRAP across the entire Delhi-NCR on 17 January 2026 after Delhi's AQI rose from 400 at 4 PM to 428 at 8 PM.
Summary
The Commission for Air Quality Management (CAQM) invoked the 5-point action plan under Stage IV ('Severe+', AQI above 450) of the Graded Response Action Plan (GRAP) across the entire Delhi-NCR on 17 January 2026. Delhi's average AQI had risen from 400 at 4 PM to 428 at 8 PM, which CAQM attributed to a Western Disturbance and calm winds. Stage IV measures include stopping the entry of BS-IV trucks into Delhi, while LNG, CNG, electric and BS-VI trucks remain allowed. CAQM revoked Stage IV three days later, on 20 January.
Key facts
- Date
- 17 January 2026
- Area
- Entire Delhi-NCR
- Delhi AQI
- 400 at 4 PM; 428 at 8 PM
- Causes
- Western Disturbance, calm winds
- Stage IV
- 'Severe+' (AQI above 450)
- Trucks
- Entry of BS-IV trucks stopped; LNG/CNG/electric/BS-VI allowed
Practice MCQs 3 questions
GRAP Stage IV, invoked across Delhi-NCR on 17 January 2026, corresponds to which AQI category?
Show answer
Correct answer: D — 'Severe+' (AQI above 450)
PIB (Environment): Stage IV of GRAP is 'Severe+', AQI above 450.
To which meteorological factors did CAQM attribute the rise in Delhi's AQI on 17 January 2026?
Show answer
Correct answer: A — A Western Disturbance and calm winds
PIB (Environment): CAQM cited a Western Disturbance and calm winds.
Which of the following trucks remained allowed to enter Delhi under the GRAP Stage IV measures invoked on 17 January 2026?
Show answer
Correct answer: C — BS-VI trucks
PIB (Environment): entry of BS-IV trucks was stopped, while LNG, CNG, electric and BS-VI trucks were allowed.