Data highlight a potential gap in India's air-quality monitoring network at a time when pollution remains a major public-health concern across several regions. Several air-quality monitoring stations across Delhi stopped reporting data on Diwali night as PM2.5 levels surged, raising concerns about gaps in the capital's pollution-monitoring. Delhi pollution data went missing during peak Diwali smog, while CPCB and DPCC showed conflicting PM2.5 readings across the city.