Delhi residents woke up to thick smog and 'severe' air quality with an AQI of 432, as per CPCB data.Several areas in Delhi recorded 'severe' AQI, with Anand Vihar at 473, Dwarka at 457, and RK Puram at 457.Neighboring cities of Ghaziabad, Noida, and Gurugram also experienced bad air quality.An episodic event of dense fog led to the 'severe' category, and IndiGo issued a travel advisory due to reduced visibility.