Best Diwali AQI in 8 years: As firecrackers were set off in defiance of the prohibition on Sunday night, PM10 and PM2.5 levels skyrocketed in various parts of the city.
At certain sites, the hourly PM10 levels were 15–16 times higher than the 24-hour standard. When the 24-hour standard is 100 µg/m3, the PM10 concentration at the Jawaharlal Nehru Stadium monitoring station peaked at 1632 µg/m3 at 2 am. The Delhi Pollution Control Committee (DPCC) released statistics showing that the level dropped to 467 µg/m3 by 8 am on Monday, after remaining over 1000 µg/m3 from 11 pm to 4 am.
Similarly, on Sunday night and early Monday morning, the hourly PM2.5 readings at Jawaharlal Nehru Stadium were more than 20 times higher than the 24-hour average. At two in the morning, when the 24-hour standard is sixty µg/m3, the PM2.5 concentration peaked at 1423 µg/m3. By 8 am, the level had dropped to 383 µg/m3.
Best Diwali AQI in 8 years
On Sunday night, pollution levels in RK Puram also spiked. At 7 pm, the PM10 concentration was 165 µg/m3, but by 11 pm, it had skyrocketed to 1380 µg/m3. By Monday morning at 8 am, this has dropped to 405 µg/m3.
The city’s 24-hour average, or AQI, dropped from 218 at 3 pm on Sunday to 283 at 8 am on Monday, still falling into the “poor” category. At 8 a.m. on Monday, the 24-hour average AQI at a few monitoring stations fell into the “very poor” (301 to 400) range. For example, the AQI was 341 at Jahangirpuri and 315 at Lodhi Road.
The city’s air quality remained in the “severe” category due to the winds and rainfall brought about by a western disturbance last week, which helped wash away contaminants that had accumulated there. This also meant that the city recorded the highest level of air quality on Diwali Day in the previous eight years. At 4 p.m. on Sunday, the 24-hour average AQI was 218—in the “poor” range. On Diwali day of last year, the AQI was 312. In 2021, it was 382; in 2020, it was 414; in 2019, it was 337; and in 2018, it was 281. The AQI on Diwali day in 2015 was 342; in 2016, it was 431; and in 2017, it was 319.