Several climatological regions of India had an unexplained trend in air quality during the winter of 2022–2023, which coincided with the retreating phase of the extraordinary triple dip La Niña. 

This tendency had not been seen in previous decades.

The air quality in South-Western India was exceptionally poor, while the air in the heavily polluted North of India was comparatively better, with levels of PM2.5, the most harmful particle, differing by up to 30% from previous years.

Peninsular India experienced pollution trapping due to the greater northerly winds that dominate the transport level. 

This resulted in an influx of air and slower winds near the surface, which significantly raised PM2.5 concentrations.

On the other hand, the Northern air quality significantly improved due to comparatively weak western disturbances, distinct wind patterns without rain or clouds, and quicker ventilation.