From World’s Second-Most Polluted To AQI 121: Delhi’s Cleaner October Offers Hope But Winter Pollution Battle Is Far From Over

New Delhi: A spell of heavy rainfall brought a sharp improvement in Delhi’s air quality on Friday, with the Air Quality Index (AQI) dropping to 121 after the capital ranked as the world’s second-most polluted city on Thursday, behind Lahore. While the showers offered temporary relief from pollution, environmental experts cautioned that the decline was largely weather-driven and did not indicate a sustained reduction in emissions.

The improvement followed rain and thunderstorms triggered by an interaction between the remnants of Cyclone Arnab and a western disturbance, which also brought an unusual dip in temperatures across the national capital. On Thursday, October 29, Delhi recorded its coldest October day in four years, with the maximum temperature at Safdarjung, the city’s base weather station, settling at 25.

4°C.The rainfall helped wash suspended particulate matter out of the atmosphere, bringing down pollution levels after several days of deteriorating air quality. The AQI near India Gate also entered the ‘Satisfactory’ category following the showers.

However, experts warned that pollution could rise again once the rain subsides and unfavourable winter conditions begin to trap pollutants close to the ground. They stressed that sustained emission reductions, rather than intermittent weather events, would be crucial to improving Delhi’s air quality over the coming months.