On Monday, Delhi recorded the lowest air quality index (AQI) — a measure of pollutants — for the month of August since records began in 2015, as per data from the Central Pollution Control Board (CPCB).
The AQI in the city on Monday was 41, which is considered to be in the ‘good’ category — ranging from 0 to 50. In the past month, the AQI has not gone above 87, which is considered to be in the ‘satisfactory’ range from 51-100, and there were also four ‘good’ air quality days.
In the previous five years in the month of August, ‘good’ air quality days have not been recorded in the city, except in 2019 when there were two. However, air quality during the monsoon season largely remains in the satisfactory range as rain helps settle down pollutants that remain suspended in the air and strong winds help in dispersion.
The issue of poor air quality in Delhi crops up closer to winter months when wind speed remains low, and cold weather and fewer sunny days hinder dispersion of pollutants. This is in addition to the contribution of pollutants from stubble burning in northwest Indian states.
Experts have said that a reason behind improved air quality is that movement of people and vehicular traffic has not returned to the level it was in the pre-coronavirus period.
Rainfall in Delhi this past month has also been the highest in the month of August for the past seven years. The city recorded 237 mm rainfall last month, which is significantly higher than 119.6 mm recorded in August 2019 and 206.5 mm in 2018.
Rain during August 2017 was recorded as 152.2 mm and 122.1 in August 2016. In August 2015, there was 195.4 mm rainfall.