The latest Monthly Ambient Air Quality Snapshot for India (August 2025) shows Shillong as the cleanest city in the country, with a PM2.5 level of just 3 µg/m³ in August, far below national and WHO standards. In contrast, Byrnihat on the Assam-Meghalaya border recorded 66 µg/m³, the country’s worst. The Meghalaya govt has ordered an audit of industries.