Delhi's air quality remained "poor" for the third day on Saturday and is likely to deteriorate further, even as experts said the situation is better than corresponding periods in the last few years.
The centre-run System of Air Quality and Weather Forecasting and Research (SAFAR) recorded the overall air quality index (AQI) at 221, which falls in the poor category.
The Central Pollution Control Board, too, recorded the overall AQI at 222 at 4 pm.
The city's AQI is predicted to deteriorate to 256 on Sunday.
SAFAR said Delhi's pollution levels will move towards "very poor" by third week of October.
A senior official said the air quality is not likely to deteriorate drastically for the next two to three days as the wind speed is not enough to transport smoke from the burning of stubble in Haryana and Punjab to Delhi.
SAFAR said the AQI is still much better than the last few years in this time of the year, partly due to enough widespread moisture with relatively warmer temperatures around the surrounding areas of Delhi.
"Delhi's air quality was recorded in the ''satisfactory'' category till October 2 and in the ''moderate'' category till October 9. It turned poor for the first time in the season on Thursday.
"Last year, the city's air quality had turned very poor on October 7," the official said.
SAFAR said the increased biomass fire counts in Haryana and Punjab are likely to influence Delhi''s AQI now.
"The surface wind speed continues to be slow and variable with predominant direction from the West. Under these conditions, air quality is predicted to deteriorate to the middle of the poor category by Sunday. Further deterioration of the AQI is expected by October 14," it said.
Starting October 15, stricter measures to fight air pollution will come into force in Delhi and its neighborhood as part of the Graded Response Action Plan, which was first implemented in Delhi-NCR in 2017.