The level of suspended particulate matters, PM 2.5 and PM 10, have seen a 'steady fall' in Delhi's air despite a drastic fall in the temperature over the last four days, which has the potential to elevate the quantity of such pollutants.

A System of Air Quality and Weather Forecasting and Research study termed it as the 'first good indicator' of the season and said a 'sudden fall in influx of emissions' may explain the fall.

The average level of PM 2.5 has been 129 microgram per cubic metre of late, still 'very poor', which at this time last year was 196 with not only the minimum temperature in the same range but also much lesser maximum temperature (16C as opposed to last year's 24C).

A dip has also been observed in the real-time readings of Delhi Pollution Control Committee, SAFAR and Central Pollution Control Board figures where the air quality index hovered between 'moderate', 'poor' and 'very poor'.