A thick blanket of fog shrouded Delhi on Sunday, lowering visibility to 100 metres and affecting traffic movement, the India Meteorological Department (IMD) said.
Dense fog reduced visibility to 200 metres at Safdarjung and 100 metres at Palam.
According to the IMD, very dense fog is when visibility is between 0 and 50 metres. In case of dense fog, visibility is between 51 and 200 metres, moderate 201 and 500 metres, and shallow 501 and 1,000 metres.
Dense to moderate fog is predicted in Delhi for the next four days, the IMD said.
The city's minimum temperature, however, rose to 8.8 degrees Celsius, a notch above normal, due to easterly winds and a cloud cover over the city, an IMD official said.
Easterly winds are not as cold as northwesterly coming in from the snow-clad western Himalayas, while clouds trap some of the outgoing infrared radiation, increasing the minimum temperature.
The mercury is predicted to drop to four degrees Celsius by Tuesday as dry, icy winds have started blowing from the snow-clad western Himalayas towards the plains, the IMD official said.