Why post-Diwali air was cleaner in Delhi this year?

The pollution level in Delhi remained relatively low a day after Diwali with the 24-hour average AQI reaching 360 on Friday. Anumita Roychowdhury from Research and Advocacy at the Centre for Science and Environment, said, "Diwali was in October, when cooler meteorological conditions had not settled in yet. The wind speed was also favourable to help dissipate the pollution build-up."