While some trains like Lalquila Express, Lichchavi Express and Sampoornkranti Express were running 12 hours behind the schedule, Purushottam Express was delayed by 11 hours due to the foggy condition.
According to Northern Railway, the poor visibility has affected services of total 67 trains in the region.
Rajdhani trains for Bhubaneswar, Kolkota, Ranchi, Patna and Shatabdis for Kanpur and Kalka have been affected due to the fog.
Services of Jansadharan Express and Rohtak Intercity Express are among three trains cancelled due to the fog.