Delhi recorded its best air quality in 55 days on Thursday, courtesy rains and high-velocity winds that kept pollution in check.
The city recorded its overall air quality index at 106, the best since October 5, when it was 98. On Wednesday, the overall AQI was 134.
In Delhi and National Capital Region (NCR), the level of PM2.5 -- tiny particulate matter less than 2.5 microns in diameter that can enter the lungs and the bloodstream -- was 37.5 microgram per cubic metre at 7.30 pm, which is within the safe limit of 0-60.
The region had last recorded such levels on October 5.
Most of the 37 air quality monitoring stations in Delhi recorded AQI in the "satisfactory" category. Pusa registered the best AQI of 64.
An AQI between 0-50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor' and 401-500 'severe'. An AQI above 500 falls in the 'severe plus' category.
Weather experts said parts of Delhi and its suburbs received rains on Wednesday and Thursday, improving the air quality further. Also, the share of stubble plume in Delhi's pollution was negligible as Punjab and Haryana received light rains for the third consecutive day on Thursday, they said.
Mahesh Palawat, a senior scientist at Skymet Weather, a private forecaster, said with the western disturbance moving towards east, the wind direction in northern plains will change to northwesterly and wind speed will dip.
"But that won't affect the air quality much. The AQI is expected to remain in the moderate category on Friday," he said.
Most areas in neighbouring Haryana and Punjab recorded "satisfactory" or "good" air quality as winds gusting up to 15-20 kilometers per hour have been clearing the pollutants in Delhi-NCR faster.
The Centre-run System of Air Quality and Weather Forecasting and Research (SAFAR) said, "AQI is likely to deteriorate to poor category on Friday. The estimated fire count is 147 and transport-level winds are easterly. Hence, no significant stubble impact is expected in Delhi in the next 24 hours.