Rain, traffic curbs help Delhi log year’s first good air day

Delhi’s air quality improved to its best levels in 11 months on Sunday, as a strong spell of overnight rain and sparse vehicular traffic due to G20-related restrictions combined to give the national capital unusually low pollution levels.

The Capital’s 24-hour average air quality index (AQI) dipped to 45 at 4pm on Sunday, the city’s first “good” air day this year. Pollution levels on Sunday were the lowest since October 10 last year, when Delhi clocked an AQI of just 44.

Delhi also got 38.6mm rain in the 24 hours till 8.30am on Sunday, with another 1.3mm till 5.30pm.

Sunday’s air quality improved from 54 a day ago, which was the year’s lowest so far. The AQI was 83 on Friday and 104 on Thursday.

Also Read: IMD predict prolonged spell of light rainfall in Delhi NCR, central India next few days

The Central Pollution Control Board (CPCB) classifies an AQI of 50 or lower as ‘good’, between 51 and 100 as ‘satisfactory’, between 101 and 200 as ‘moderate’, between 201 and 300 as ‘poor’, between 301 and 400 as ‘very poor’ and over 400 as ‘severe’.

The vastly improved air coincided with the G20 Summit, during which vehicular movement was disallowed and public spaces shut in the central Delhi region.

Officials said clean-up drives and sprinklers used consistently in the run-up to the global event helped wash Delhi’s characteristically polluted air. Last year, at the same time, Delhi’s AQI was 141on September 9 and 110— both in the moderate category —the day after.

Strong winds that accompanied the rain also helped wipe the air of pollutants, said officials and experts.

Anumita Roychowdhury, executive director, research and advocacy at the Centre for Science and Environment (CSE) said the improvement in air quality was due to a combination of various factors including meteorological conditions and reduced emissions on account of G20 curbs.

“There were several restrictions due to the G20 summit, including offices and institutes being shut, and much lower traffic volumes. Efforts such as clean-up drives were also taken to keep pollution in check. Moreover, we saw intense rain on Saturday. All these factors together played a role in the current spell of good air,” said Roychowdhury.

On Sunday, the Safdarjung observatory, Delhi’s base weather station, recorded a maximum temperature of 28.3°C, five degrees below normal.

The minimum temperature, meanwhile, was 23.5°C, two below normal.

According to CPCB data, 2022 saw three good air days all year. In 2021, Delhi clocked just a single such day. In 2020, however, when the city was under Covid-19 curbs for much of the year, Delhi clocked five “good” air days.

Other cities in the National Capital Region (NCR) also recorded relatively better air quality as the AQI was 34 in the ‘good’ category in Ghaziabad, 70 in Gurugram, 51 in Greater Noida, 62 in Faridabad, and 32 in Noida.