On Saturday, Delhi recorded a minimum temperature of 7.2 degree Celsius; the maximum temperature was recorded at 22.6 degree Celsius.
The passengers had driven through fog-covered roads to the airport but the operations at the airport were severely affected for around five hours in the morning, as the runway visibility dropped below 50 metres. Save for a couple of worldwide flights, all other flights that were heading North were delayed, they said. This year's worst condition of fog has been experienced.
On Sunday moring, over 40 flights were diverted to other airports and several were cancelled.
In neighbouring Rajasthan, at least four people were killed and four injured when their vehicle fell into a pond due to low visibility caused by fog in Bharatpur's Dig.More news: Raiders fire head coach Jack Del Rio after disappointing 6-10 finish
As many as 20 flights were delayed and six were cancelled, while 64 trains were delayed, 24 were rescheduled and 21 cancelled, ANI reported.
The maximum temperature is likely to hover around 22 degrees Celsius, he said. The visibility later improved to 100 metres at 3 a.m. and to 200 metres at 6 a.m.
Apart from the chilly weather and the dense fog, Delhi also witnesses poor air quality. The heavy blanket of fog engulfed the national capital region on the New Year morning.
Departures require visibility of at least 125 metres, while planes can land when visibility is below 50 metres if pilots are trained in the use of CAT IIIB. Low visibility also affected train services in the morning, with over 90 delayed, cancelled and re-scheduled due to the dense fog.