With slow moving winds and dense fog and low temperatures, the air quality in Delhi has slipped to 'severe' category on Friday. As per record, the overall air quality index (AQI) in Delhi was 432 on Friday, considerably high from Thursday's 362 (very poor).

Delhi on Sunday celebrated Diwali with crackers and cheers, pushing air quality here into 'severe' zone. The Centre's System of Air Quality and Weather Forecasting and Research (SAFAR) recorded the level of respirable pollutants, PM 2.5 and PM 10, at 283 and 517 micrograms per cubic metre respectively at around 8 pm, violating the safe limits multiple times.