India, Jan. 21 -- The Commission for Air Quality Management (CAQM) on Tuesday lifted stage-4 of the Graded Response Action Plan (Grap) after the air quality improved marginally. The 24-hour average air quality index (AQI) stood at 378 (very poor) at 4 pm - down from a reading of 410 (severe) at 4 pm on Monday, snapping a three day streak where the AQI had been 400 or higher.

It was 440 (severe) on Sunday and 400 (very poor) on Saturday.

Forecasts show Delhi's AQI is now set to remain 'very poor' in the coming days, even as a western disturbance approaches, bringing possible light rain and gusty winds on January 23.

"Delhi's air quality is likely to be in the 'very poor' category from January 21 till January 23. The outlook for the subs...