According to the AQI monitoring agency aqi.in, Punjab’s Kapurthala and UP's Ghaziabad witnessed the worst air quality on Thursday with an AQI of 389 and 346, respectively. These were followed by Nagli Bahrampur (336), Baddi (331), Saharanpur (321), Haripur (318), Bulandshahr (318), Gurugram (316), Begampur (309), and Nawanshahr (309). AQI in all these cities remained in the ‘very poor’ category.