Various weather factors play an important role in increasing or decreasing pollution as well as in variation of temperature. AQI of Delhi and NCR was in poor to very poor category during last few days. Air quality deteriorated to severe category on couple of occasions in November.
Today on November 15 at 10:00 a.m. Pm 10 was at 190 and pm 2.5 was at 97. Reason for this reduction of pollutants can be attributed to the change in wind direction and speed. Since the last two days, winds have been blowing from northeast and southeast direction. Punjab and Haryana are in northwest of Delhi therefore, these winds are blocking the smoke of stubble burning from Punjab and Haryana.
The Western disturbance is moving across the Western Himalayas. After the passage of Western disturbance, the normal flow of cold north westerly winds will resume over North West India including Delhi. These cold winds will be blowing from snow clad mountains of Western Himalayas and will be instrumental in dropping the minimums.
Winter chill will set in soon as temperatures are expected to drop by 3 to 5 degrees during next 2 to 3 days. Although number of farm fires over Punjab and Haryana has reduced significantly but a small percentage of smoke may travel towards Delhi with these northwesterly winds.
Thus, we can expect marginal increase in pollution and decrease in temperature.