New Delhi, Jan 18 (IANS): The national capital saw a little improvement in its air on Friday as the overall Air Quality Index (AQI) turned from 'severe' to 'very poor' due to an increase in the wind speed.

Experts say that the AQI for Delhi is likely to improve marginally but it will still remain in the 'very poor' range for the next three days.

"We could see a rapid improvement in the air quality if Delhi gets sufficient amount of rain from the predicted western disturbance over northwest India," the System of Air Quality and Weather Forecasting and Research (SAFAR) said.

The India Meteorological Department (IMD) has forecast light rainfall with gusty winds or thundershowers over the national capital region over the next week, which could wash away the pollutants and bring the air quality in 'poor' zone.

However, SAFAR has cautioned that if only light rains occur in Delhi, it will aggravate the situation.

The agency has also forecast continuation of dense to very dense fog over some areas of Delhi which, it says, is not good for air quality as "it will resist pollutants to disperse".

The overall AQI of Delhi at 4 p.m on Friday was recorded at 397, against Thursday's 'severe' air quality at 440.

In the National Capital Region, only Faridabad and Gurugram improved to 'very poor' category. Ghaziabad, Greater Noida and Noida continued to remain in the 'severe' category with AQI at 412, 416 and 405, respectively.

On Friday, across 35 areas in Delhi where pollution is actively monitored, the average concentration of PM 2.5 and PM 10 was 236 and 362 microgrammes per cubic meter, respectively.

The concentration of PM 2.5 and PM 10 across 48 monitoring stations in the NCR stood at 224 and 348 microgrammes per cubic meter, respectively.