New Delhi, Jan 23 (IANS): After a day of receiving intermittent rain, Delhi's air quality on Sunday improved significantly as its Air Quality Index (AQI) stood at 169 under the 'moderate' category, according to the System of Air Quality and Weather Forecasting And Research (SAFAR).

An AQI between zero and 50 is considered 'good'; 51 and 100 'satisfactory'; 101 and 200 'moderate'; 201 and 300 'poor'; 301 and 400 'very poor'; 401 and 500 'severe.'

The level of both PM 2.5 and PM 10 pollutants stood in the 'moderate' categories, even post noon.

Delhi's AQI was recorded in the 'very poor' category since the second week of January. It had improved and settled in the 'moderate' category at the beginning of the month as the national capital received light rain.

From Monday onwards, fair weather conditions are likely to prevail with normal emissions from anthropogenic activity partially offset by moderate ventilation resulting in the gradual accumulation of pollutants bringing AQI back to 'moderate' or 'poor', SAFAR said.

The air quality and weather bulletin said that the predominant surface wind is coming from the southeast direction of Delhi with wind speed 08-16 kmph on Sunday.

"The predominant surface wind is likely to be coming from northwest direction of Delhi with wind speed 08 kmph, partly cloudy sky and moderate fog in the morning on Monday. The predominant surface wind is likely to be coming from the northwest direction of Delhi with wind speed 06-10 kmph, partly cloudy sky and moderate fog in the morning on January 25," it added.