New Delhi, Oct 5 (IANS): Delhi's overall air quality has been in moderate category, but is set to deteriorate further in the coming days, thanks to stubble burning, SAFAR warned on Monday.

"A sharp increase in stubble burning fires observed yesterday (Sunday) around Punjab, Haryana, and neighbouring border regions and boundary layer wind direction is favourable for transport... as the ventilation coefficient decreases, stubble burning starts to impact Delhi in the coming days," the System of Air Quality and Weather Forecasting And Research (SAFAR) said.

It said there will be a "marginal improvement" in Delhi AQI on Tuesday. However, further AQI will "marginally deteriorate" and stay at the moderate category for the next two days.

According to the Central Pollution Control Board, Delhi's AQI at 3 p.m. on Monday has been 176. Average PM 2.5 level was 105 microgrammes per cubic metre.

Stubble burning causes a smog-like situation in Delhi NCR every year post autumn, creating a health hazard for its residents.