Mizoram's Aizawl was the cleanest city in India in January this year with an average monthly PM2.5 of 9 µg/m³, according to a Centre for Research on Energy and Clean Air (CREA) report. It was followed by Karnataka's Gadag, with an average monthly PM2.5 of 12 µg/m³ and Uttar Pradesh's Bareilly, with an average monthly PM2.5 of 18 µg/m³.