Delhi's air quality falls to season's worst, visibility drops to 150 metres

A thick layer of smog covered Delhi as the city's air quality deteriorated to the season's worst on Monday morning. Delhi' air quality plummeted to the "severe-plus" category with the 24-hour average Air Quality Index (AQI) soaring to 481, the highest this season. The visibility also fell to 150 metres in parts of Delhi, causing delays and disrupting flight operations.