Delhi today experienced the coldest day of the season with temperatures dropping as low as 5 degrees Celsius, the Met Office said. The maximum temperature was recorded at 20.3 degrees Celsius, a notch above the normal, it said. Dense fog curtailed visibility to below 50 metres at 5.30 AM and improved slightly to 50 metres by 8.30 AM. The weather conditions led to disruption of flight and train services. 92 trains were running late, 44 were rescheduled and 19 cancelled, a railways official said. As many as 198 flights, including international, were delayed due to the fog at the Indira Gandhi International Airport in Delhi, airport officials said. Another 11 flights, both flying into and out of the IGIA, were cancelled due to low visibility, they said. However, as the day progressed, the visibility improved significantly to 1,500 metres, an official of the weather department said. Relative humidity oscillated between 100 and 53 per cent. The weatherman has forecast dense to very dense fog tomorrow morning. "The maximum and minimum temperatures are expected to hover around 20 degrees Celsius and 6 degrees Celsius, respectively, tomorrow," the official said. Yesterday, the maximum and minimum temperatures were recorded at 18.4 and 7.4 degrees Celsius, respectively.