Delhi-NCR air quality likely to worsen after Diwali
Historical data shows the average air quality index increases by 16 per cent in the four days following the festival.
Air quality in the Delhi-NCR region is expected to decline sharply in the coming days, according to an analysis by The Times of India. Data since 2015 indicates that the average air quality index (AQI) rises by 16 per cent during the four days after Diwali compared to the four days before the festival.
In 10 of the 11 years since monitoring started in Delhi, pollution levels were higher after the festival than before it. The number of severe air days has also tripled in the post-festival period, with 15 such days recorded since 2015 compared to five in the four days leading up to the event.
The three days before Diwali this year saw an average AQI of 373, which is the highest pre-festival level in a decade. In 2023, the average AQI rose from 289 before the festival to 393 in the four days after, representing an increase of over 36 per cent.
Similar patterns were noted in 2021, when the average AQI went from 320 to 429. In 2018 and 2019, post-Diwali pollution levels were 33 per cent and 31 per cent higher, respectively.
Environmental experts have noted that firecracker emissions occur during unfavourable weather conditions in north India during late autumn. Falling temperatures, low wind speeds, and atmospheric stagnation tend to trap pollutants near the ground.