Delhi's AQI deteriorated to the 'severe' category on Friday, with CPCB dashboard showing it at 403 at 8 am. The 24-hour average AQI stood in the 'very poor' category at 350 on Thursday, its highest since Diwali. The capital recorded AQI averages of 376 on November 8, 344 on November 9, 299 on November 10 and 313 on November 11.