India, Nov. 9 -- Air quality across Haryana collapsed to hazardous levels following Diwali celebrations, with 15 of 23 monitored cities hitting 'severe' air quality index (AQI) levels between 401 and 500 overnight, according to Central Pollution Control Board (CPCB) data. Several NCR and non-NCR cities recorded peak AQI readings of 500 between midnight and 2am due to widespread firecracker violation.

The post-Diwali surge extended well beyond Delhi border towns. Cities across central and northern Haryana-including Karnal, Ambala, Kurukshetra, Kaithal, Sirsa, and Panipat-reported steep spikes in pollutant concentrations.

Conditions failed to improve by Monday morning. Bahadurgarh recorded an AQI of 401, followed by Charkhi Dadri (388), R...