Patna Air Quality (AQI)

Patna sits at the heart of the Indo-Gangetic Plain (IGP) — a 2,500 km flat alluvial basin bounded by the Himalayas to the north and the Deccan Plateau to the south. This geography creates a natural pollution trap: emissions from millions of sources across Bihar, Uttar Pradesh, Punjab, and Haryana accumulate in the plain with nowhere to disperse vertically during winter.

The Himalayan barrier prevents cold Arctic air from moving south, but allows warm air aloft to settle over the basin — creating a classic temperature inversion. Warm air above, cold stagnant air below, with the pollution layer trapped at breathing height for days at a time. Patna experiences 40–60 such inversion events per winter, each lasting 3–8 days.

Crop burning adds a catastrophic seasonal overlay. Post-harvest burning of rice and wheat stubble in Punjab and Haryana (October–November) releases 13+ million tonnes of air pollutants annually. Prevailing westerly winds carry this smoke plume 1,000–1,500 km eastward across Uttar Pradesh directly to Bihar. Patna's AQI can jump from 150 to 400+ within 24 hours when a major crop fire front reaches the city.