"A clear day lies ahead for Delhi. However, it will get colder towards the evening," an India Meteorological Department (IMD) official said.
The day temperature is likely to be around 21 degrees Celsius, the officials added.
Humidity at 8.30 a.m was 97 per cent.
A railway official said 10 trains were cancelled and 36 were running behind schedule due to fog in the country's northern region.
"Thirty-six trains are running behind schedule by several hours and 10 trains have been cancelled today (Thursday) morning. Dense fog in northern parts of India affected rail services," a Northern Railway spokesperson said.
Wednesday's maximum temperature settled a notch below average at 20.2 degrees Celsius, while the minimum was three notches below average at 4.4 degrees Celsius.