The overall air quality index stood at 323 at 8 am.
Air pollution in Delhi ameliorated from "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. Delhi recorded a minimum temperature of 16.9 degrees Celsius, three notches above normal. The maximum temperature settled at 30.2 degrees Celsius.
V K 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 from the Indian Agricultural Research Institute and SAFAR, a forecasting agency under the Union Ministry of Earth Sciences.
The Delhi government had on Monday decided to reopen primary classes from November 9 and revoke the order asking 50 per cent of its staff to work from home in view of "improvement" in the city's air quality over the last few days.
However, BS-III petrol and BS-IV diesel four-wheelers were asked to stay off roads in Delhi under stage 3 of GRAP.
Violation of the ban could invite a fine of Rs 20,000. Vehicles deployed for emergency services, and government and election-related work are exempted.
The Delhi government will run 500 additional buses in the capital under the "Paryavaran Bus Sewa" campaign to bolster public transport in a bid to reduce vehicular emissions.
According to a study conducted by The Energy and Resources Institute in 2018, vehicular emissions account for around 40 per cent of the PM 2.5 pollution in the capital.
With air pollution ameliorating in Delhi, the Commission for Air Quality Management (CAQM) on Sunday directed authorities to lift the ban on plying of non-BS VI diesel light motor vehicles in the region and the entry of trucks into the capital imposed under the stage 4 of the GRAP.
It had also banned construction work in public projects such as highways, flyovers, power transmission, and pipelines in Delhi-NCR.
The CAQM order recommending the restrictions was issued on Thursday.
According to an analysis conducted by the Delhi Pollution Control Committee last year, people in the national capital breathe the worst air between November 1 and November 15 when stubble burning peaks and winters set in.
The Air Quality Life Index (AQLI) released by the Energy Policy Institute at the University of Chicago (EPIC) in June showed that residents of Delhi stand to lose 10 years of life expectancy due to poor air quality.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)