NEW DELHI: The Centre’s pollution watchdog on Saturday invoked Stage 4 curbs under the Graded Response Action Plan (GRAP) in Delhi-NCR as air quality deteriorated to the ‘severe’ category. Officials reported the AQI rising sharply from 400 at 4 PM to 428 at 8 PM, driven by a western disturbance, adverse weather conditions, and poor pollutant dispersal.
A senior official of the Commission for Air Quality Management (CAQM) said the Sub-Committee on GRAP decided to implement all Stage-IV actions for ‘Severe+’ air quality (AQI above 450) as a proactive measure. This follows GRAP 3 restrictions enforced on Friday. GRAP categorises air quality into four stages: ‘poor’ (201–300), ‘very poor’ (301–400), ‘severe’ (401–450), and ‘severe plus’ (above 450). Dense fog reduced visibility Saturday morning, with a minimum temperature of 4.4°C, 3.2°C below the seasonal average. The India Meteorological Department forecast a maximum of 22°C, with relative humidity at 100 per cent at 9 am.