Delhi's air quality improved from 'very poor' to 'poor' due to winds dispersing pollutants. The Air Quality Index (AQI) decreased from 330 to 286. However, it is predicted to reach the higher end of the 'very poor' category on Friday. Winds with an average speed of 18 kmph helped disperse the pollutants, but speeds are expected to decrease on Wednesday. The air quality is expected to deteriorate significantly from December 22 onward, remaining in the 'very poor' category until December 27. Delhi has not seen 'severe' air quality in December so far.