The long-distance trains were most effected due to the thick fog cover in Uttar Pradesh and parts of Bihar, he added.
Major trains running late by five-six hours included Triveni Express, Garib Rath, Purabia Express, Avadh Assam, Ganga Sutlej, Gareeb Nawaz and Shaheed Express.
Chilly weather conditions prevailed in the state with the mercury dipping to about five degrees Celsius in Lucknow, Kanpur and Allahabad Saturday. The weather office has forecast sub-zero temperatures in some regions by the year end.
Saturday's minimum temperature in Lucknow was five degrees Celsius, while it was 5.4 and 5.2 degrees Celsius in Allahabad and Kanpur, respectively, a weather official said.
Muzaffarnagar was the coldest in Uttar Pradesh at 2.7 degrees Celsius, followed by Najibabad (3.5 degrees Celsius) and Agra (4.2 degrees Celsius).
The average maximum temperature in the state Saturday was 17 degrees celsius, which was six notches below the normal for this time of the season.