Delhiites on Wednesday woke up to the coldest morning this season when the mercury dipped to the season's lowest of 4.5 degree Celsius.
The temperature was two degrees below normal, a Met Department official said.
Over the last two days, the minimum temperature in the Capital has dropped by more than one degree.
The bone-chilling conditions were made worse by a thick fog enveloping the city in the early hours, delaying flights and forcing the cancellation of trains.
The minimum visibility in the Palam area, where the airport is located, fell to near zero levels at 0900 IST, the Met official said.
All flight operations were normal up to 0730 IST. But, after that, the thickening fog caused delays in some flights, an Airport Authority of India spokesman said.
The visibility was low in other parts of the city, too, forcing vehicles to ply with fog-lights and blinkers on.
Railway services continued to be the worst affected. A Northern Railway statement said eight trains, including the Howrah-Delhi Janta Express, were cancelled on Wednesday.
