After weeks of "very poor" and "severe" air, Delhi and adjoining areas witnessed their first improved air quality day of 2019 with the quality index (AQI) recorded at 'poor' levels of 288 due to a sudden increase in the wind speed.
"Overall air quality in Delhi is in the poor category and it is likely to remain in the same zone as surface winds continue to play a major role in dispersing the pollutants," System of Air Quality and Weather Forecasting And Research said in its daily pollution analysis.
The agency said the wind speed in Delhi-NCR increased overnight from 3 kmph per hour to 5 kmph and continued to disperse pollutants despite the cold weather.
SAFAR, however, added that the air quality is predicted to be in the "poor" zone on Thursday but it might enter the "very poor" zone again from Friday before getting under the influence of predicted weekend rainfall.
Delhi's AQI at 4 p.m. on Wednesday was recorded at 288 (poor), a drastic drop from Tuesday's 320.
In the National Capital Region (NCR), Faridabad and Ghaziabad at 288, Noida at 264 and Gurugram at 243 also fared in the "poor" category. However, Greater Noida was unaffected by the wind speed as its AQI remained in the 'very poor' zone (302).
When the AQI is recorded between the range of 201 and 300, it is recorded in the 'poor' category; between 301 and 400, air quality is categorised as 'very poor', and between 401 and 500, the air pollutants are considered at 'severe' levels.
The average concentration of PM2.5 and PM10 in Delhi was 149 and 255 microgrammes per cubic meters on Wednesday. Across NCR, it was 148 and 240 units respectively.
Since the beginning of the year, the air quality in Delhi and adjoining areas have been oscillating between 'severe' and 'very poor' zone.
The AQI in Delhi dropped to the "severe" zone thrice in the first seven days of 2019. Although light rainfall during January 5 and 6 brought some relief to the national capital, the AQI still remained in the 'very poor' zone due to excessive moisture in the air.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)