Delhi air quality improves to 71 but the clean air may not last

Data from CPCB shows the capital’s daily average AQI has improved to 71 on Friday from 85 on September 2 and 113 on Sept 1

Despite recording only isolated rainfall since the start of September, Delhi’s air quality has steadily improved, driven largely by strong winds, according to experts and official data.

Recently, the wind speed has picked up, which has caused the pollutants to disperse. (HT Photo/Sanchit Khanna)

Data from the Central Pollution Control Board (CPCB) shows the capital’s daily average Air Quality Index (AQI) stood at 113 (“moderate”) on September 1, before improving into the “satisfactory” category with readings of 85 on September 2 and 74 on September 3. On Friday, September 4, the average AQI improved further to 71.

The CPCB classifies AQI between 0 and 50 as “good”, 51 and 100 as “satisfactory”, 101 and 200 as “moderate”, 201 and 300 as “poor”, 301 and 400 as “very poor”, and above 400 as “severe”.

Experts attributed the cleaner air to strong wind.

“For the past five to six days, the pollutants in the air had been clumped together, causing a haziness of sorts. Recently, the wind speed has picked up, which has caused the pollutants to disperse. Additionally, some rain has occurred in the city, which has also contributed,” said Ashwary Tiwari, founder of Indiametsky Weather.

“As rains subside in the city in the coming few days, the AQI will increase. For the rest of the month, we are expecting the AQI to continue fluctuating, following the rain’s cue. Since there is not much rain predicted during September this year, we are expecting the yearly high AQI period to start from the end of the month,” he said.