Sporadic rains in nearby states, Delhi’s air quality improves

New Delhi, November 9

The air pollution in Delhi ameliorated from the “very poor” to the “poor” category on Wednesday, owing to favourable wind speed at night, sporadic rains in adjoining states and a considerable drop in emissions from stubble-burning.

The 24-hour average AQI stood at 260, dropping from 372 on Tuesday. It was 354 on Monday, 339 on Sunday and 381 on Saturday. This is the lowest AQI since October 20 when it was 232. For November, it was the best AQI since November 29, 2020, when it was 231, according to data from the Central Pollution Control Board.

An AQI between 201 and 300 is considered “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.

The improvement in air quality was evident from better visibility levels with 1,400 metres at the Palam airport and 1,500 at the Safdarjung airport in the morning. A smoky haze had lowered the visibility levels to 800 metres at these places on Tuesday.

A Met official said southeasterly winds gusting up to 30 kmph barrelled through parts on Tuesday night. It helped improve the situation.

VK Soni, the head of the India Meteorological Department’s Environment Monitoring and Research Centre, said parts of east Rajasthan such as Alwar, Bhiwadi and Rewari and some areas in Haryana reported sporadic rains under the influence of a western disturbance affecting the hilly region in the north. “The rainfall reduced the share of pollutants from these adjoining areas in Delhi’s pollution,” he said.

Favourable wind speed —10 to 18 kmph — is predicted to bring a considerable improvement in the air quality from November 11. The Commission for Air Quality Management may also convene a meeting on Thursday to review the situation and revoke the curbs in Delhi-NCR under stage 3 (very poor air quality) of the Graded Response Action Plan.

Farm fires in Punjab increased from 605 on Tuesday to 1,778 on Wednesday. However, their share in Delhi’s PM2.5 pollution dipped from nine per cent on Tuesday to five per cent on Wednesday, according to data.