The people in Delhi welcome morning by a foggy day on Sunday, while the temperature was substantially moderate as compared to other days.The Indian Meteorological Department report said the minimum temperature to be 7 degrees Celsius and maximum temperature to be 25 degrees Celsius in the national capital.At least 17 trains were off, 19 arriving late and six unscheduled after a blanket of fog engulfed Delhi today.The Air Quality Index in major areas of the city continued to be in "very unhealthy" category. The passengers have been informed to check the train status of the train before undertaking their journey.The status of these trains will also be broadcast to the passengers on their respective registered mobile numbers.The fog makes the visibility very low and trains have to run at a highly-restricted speed to ensure the safety of the passengers which leads to considerable delays in the movement of trains.The status of these trains will be observed periodically keeping in view the strength of fog and decisions to restore some of the trains may be taken, as and when operationally feasible.The national capital Delhi had been experiencing chilling cold since the past few days.People took the safety at night shelters in Delhi on Thursday and light fire to keep themselves warm.