New Delhi, Nov 21 (IANS): Delhi's air quality remained 'very poor' for the fourth straight day on Wednesday, and is likely to remain in the same category for the next few days.

"Air quality is in the upper range of 'very poor' and is expected to remain within the same category for the next 2-3 days," said a forecast by the System of Air Quality and Weather Forecasting And Research (SAFAR).

On Wednesday, the Air Quality Index (AQI) of Delhi was 373, the same as on Tuesday, with no relief in sight.

Official reports claim that now stubble burning in the neighbouring states only have a "marginal impact" on the air quality of Delhi.

Delhi is suffering from its local pollutants and the prevailing weather conditions are allowing the pollution to accumulate.

"At present, wind speed is slow, which allows the pollutants to get accumulated. Humidity too is still high, which is slightly unfavourable," SAFAR said.

The average presence of the major pollutant PM2.5 was 240 microgrammes per cubic meter in Delhi - a slight increase from 219 on Tuesday.

Across NCR, Gurugram with an AQI of 345 fell further into the 'very poor' category. The AQI was 386 in Ghaziabad, 392 in Greater Noida, and 377 in Noida.