Delhi's Diwali air was the cleanest in the last four years - AQI was the lowest since 2018 as per data from the Central Pollution Control Board. This despite crackers being burst across the capital, even with a ban and a six-month jail time in place. VK Soni, head of the Environment Monitoring and Research Centre (EMRC) of the IMD, says that primarily, it's not human efforts, but the nature's role behind the AQI fall. They say favorable weather conditions and an early implementation of the Graded Response Action Plan both helped keep pollution relatively low. But, AQI is still in the 'very poor' category and is likely to remain so for the next couple of days. Mr. Soni says the worst of October Diwali pollution is behind us.