According to the India Meteorological Department (IMD), visibility dropped to less than 300 meters in some parts of the city at 8.30 a.m.
"As a result, 25 trains were delayed, two were cancelled and two rescheduled," said a Northern Railway official.
However, the arrival and the departure of flights from the Indira Gandhi International Airport were not affected Thursday, said an airport official.
"The weather is better today (Thursday). The visibility is also better than what it was in the past two days. The flights arrival and departure are unlikely to get affected today (Thursday)," said Kapil Sabarwal, spokesperson at the IGI airport.
The IMD has forecast a sunny and clear day ahead.
The minimum temperature Thursday morning was recorded at 8.9 degrees Celsius, a notch above the season's average, while the maximum temperature is likely to hover around 22.3 degrees Celsius.
The Met Office said Delhi will experience a clear sky, but fog may return late evening.
The national capital has been witnessing dense fog since Monday and as per the Met Office, there will be no respite for the next few days.
Wednesday's maximum temperature was recorded at 23 degrees Celsius, while the minimum temperature dropped to 9 degrees Celsius.
--IANS (Posted on 19-12-2013)