The Centre's panel on Delhi-NCR's air quality on Monday revoked the Stage 2 curbs under the Graded Response Action Plan (GRAP) following a dip in pollution levels due to favourable meteorological conditions. Delhi's 24-hour average air quality index stood at 186 at 4 pm, significantly below the 300-mark that triggers Stage 2 restrictions. The India Meteorological Department and Indian Institute of Tropical Meteorology predict that the AQI will likely remain in the moderate to poor category. The Commission for Air Quality Management in NCR and adjoining areas attributes the improved air quality to better mixing height, ventilation coefficient, and "much favourable conditions for dispersion of pollutants". With the revocation of Stage 2 curbs, inter-state buses from NCR states are now permitted to enter Delhi. During winters, the Delhi-NCR region enforces restrictions under GRAP, which categorizes air quality into four stages Stage I (Poor, AQI 201-300), Stage II (Very Poor, AQI ..