New Delhi, Feb 4 (IANS): Delhi's Air Quality Index (AQI) on Friday improved to 'satisfactory' and settled at 176 from the 'very poor' category after the national capital received light rain accompanied by gusty wind the previous day.

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 10 and PM 2.5 pollutants in the national capital's air were under the 'moderate' category.

"AQI today indicates 'mderate' air quality, improved significantly from yesterday's 'very poor' air quality due to rain and gusty wind that washed out particulate matter in air. A few spells of light rain are likely today improving AQI further but to remain within 'Moderate'," the System of Air Quality and Weather Forecasting And Research (SAFAR) said in an update.

"From Fridat onwards, relatively calm surface winds are likely. Air quality is likely to degrade back to 'Poor' and then to 'Very poor' as rate of accumulation of pollutants is likely to be more than that of ventilation," it added.

According to the air quality and weather bulletin issued by the Ministry of Earth Sciences, "the air quality is likely to remain in 'moderate' to 'poor category' on February 5 and 'poor' to lower end of 'very poor' category on February 6".

"The air quality is likely to deteriorate to very poor category on February 7, but remain largely in poor category thereafter," it added.