Due to poor visibility, 28 North-bound trains were cancelled, nine rescheduled while 36 were running late as of 6 am, a senior railway official said.
"The weather stations at Lodhi Road, Palam, Ayanagar and Ridge recorded 5.2, 5.8, 6.7 and 7.4 degrees Celsius respectively," a MeT Department official said.
The visibility recorded early morning was 400 m and 50 m respectively at Safdarjung and Palam Observatories, he said.
The relative humidity at 8:30 am was 100 per cent.
The weatherman has forecast a clear sky with moderate to dense fog on Monday morning and mist in the daytime.