Delhi recorded its most polluted start to October in four years, with the air quality index settling at 166 in the ‘moderate’ category on Thursday. Data from the Centre for Research on Energy and Clean Air showed the last worse October 1 reading was in 2022, when the AQI hit 186. Of 44 monitoring stations, 37 reported moderate air and five reported poor air, according to the Central Pollution Control Board.

The Air Quality Early Warning System forecast moderate air from October 2 to 4, blaming weak ventilation and early stubble-burning incidents. The Indian Agricultural Research Institute recorded 137 farm-fire incidents across six states between September 15 and October 1. Rain expected around October 6 could briefly wash pollutants away.

Officials say the real test comes later in the month, when farm fires peak and festive emissions typically push the capital toward ‘very poor’ air. The Commission for Air Quality Management reviews the pollution situation weekly through the winter.