Weather update: Delhi temperature drops below 20°C as festive season brings winter chill

The mercury at this point sank to 18.6°C on Monday, two degrees below the norm and the first below 20°C reading this season in Delhi. India Meteorological Department officials blame the reason for this level of reading on clear night skies. Friday's minimum temperature was 20.3°C. Temperatures may remain in this range during the week ahead, said IMD.
"We have been having clear skies consecutively.". When there is no cloud cover at night, the heat from the earth's surface escapes easily and brings down the temperature," he said. An IMD official said temperatures are expected to be in the same range for another week. "From the third week of October, we might see a gradual decrease." IMD has predicted that the minimum will rise to 21°C by Monday, followed by another drop, with partly cloudy skies expected on Sunday and Monday that would affect the temperature.

Saturday's high of 34.4°C was a fraction cooler than Friday's high of 33.6°C. The last significant minimum temperature drop since March 19 had actually occurred on September 19, when the minimum had dropped to 21.1°C. Other drops were felt on September 13 and 14 as the minimum rested at 21.4°C and 21.2°C, respectively. Last year's first sub-20°C reading was on October 3 with the minimum at 18.3°C. In 2022, the first sub-20°C reading was on October 9, at 19.3°C.

The Skymet vice president, Mahesh Palawat, said that the drop in temperature at this moment is very gradual. It is happening naturally due to the change in the position of the sun. It will see a sharp dip only when there is a western disturbance and it causes snow at higher altitudes. Such a western disturbance might approach the Capital in November.

In Delhi, the air quality remained moderate. At 4 pm yesterday, AQI was 155 (moderate), one notch higher than Friday's 141. The Air Quality Early Warning System has forecast moderate AQI levels till at least Tuesday.