According to the met officials, the intense cold conditions would continue till weekend.
With very low visibility, the Indian Railways has announced the cancellation of two dozen trains till Jan 30, extending the existing deadline by another week.
Northern Railway had last month announced cancellation of some trains, including passenger trains between Pratapgarh-Lucknow, Allahabad-Lucknow and between nearby areas, till Jan 15.
The cancellation has since been extended twice.
Meanwhile many trains, including Farakka Express, Swarna Shatabdi, Lucknow Mail, Kaifiyat Express were among the 30-odd trains that were running late.
Met Office Director J.P. Gupta said: "The things should begin clearing from Jan 20 hopefully."
The Uttar Pradesh State Roadways Transport Corporation Thursday cancelled four of its buses owing to dense fog and poor visibility. These buses included buses to Gorakhpur, Delhi and Allahabad.
Meanwhile, air services continue to be hit by the weather and four flights were cancelled Wednesday.
"There is no respite in the weather conditions, in fact the fog is worse today (Thursday), the fate of flight landings and take offs is very grim today (Thursday)," an airport official told IANS.
The maximum temperature in the state capital was 15.3 degrees Celsius while the lowest was 8.4 degrees Celsius, which was one degree above normal.