Loni in Uttar Pradesh, with an annual average PM2.5 level of 112.5 µg/m³, is the most polluted city in India, according to the annual World Air Quality Report 2025. It is followed by Byrnihat, Delhi, Ghaziabad, Mullanpur Dakha, Noida and Greater Noida. India is the sixth most polluted country in the world, according to the report.