Chandigarh, Dec. 26 -- As dense fog made a comeback in the city, residents experienced the first cold day of the season on Thursday. For this region, a cold day is declared when the minimum temperature drops below 10degC and the maximum lies 4.5 to 6.4 degrees below normal. On Thursday, the maximum temperature stood at 17.4degC, 5.2 degrees below normal, while the minimum temperature dropped to 6.9degC, which was at normal. Chandigarh also saw dense fog conditions as the visibility dropped to 200 metres between 8.30 am and 11.30 am, after remaining relatively better in the early morning hours. Fog is classified as dense when visibility falls between 50 metres to 200 metres. As per the India Meteorological Department (IMD), foggy conditions will continue over the next few days. This is also the lowest that the maximum temperature has gone this season, previously going down to 18.3degC on December 20. During the day, Chandigarh was colder than Dharamshala at 23degC. While during the night, with minimum temperature at 6.9degC, the city was colder than Shimla at 8degC and Dharamshala at 9.8degC. Speaking about this, IMD Chandigarh director Surender Paul said that the dense fog has returned due to the changing wind patterns thanks to an incoming Western Disturbance (WD). Chandigarh International Airport faced major flight disruptions on Thursday as dense fog led to the cancellation of 13 flights and delays to 35 others, causing inconvenience to passengers. The cancelled departures included IndiGo flights 6E593 to Bengaluru, 6E6395 to Ahmedabad, 6E6470 to Hyderabad, 6E681 to Pune and 6E2113 to Delhi. The cancelled arrivals were scheduled from Hyderabad, Delhi, Lucknow, Mumbai, Kolkata, Ahmedabad and Bengaluru. Dense fog also led to delays in multiple trains arriving at Chandigarh railway station, officials said. The Unchahar Express was delayed by nearly four hours. The train departs at 2 pm and is scheduled to arrive in Chandigarh at 9.15 am the following day after covering the 909-km journey in about 19 hours. The Patliputra-Chandigarh Superfast Express also reached nearly four hours behind schedule. The Netaji Express, originating from Howrah in Kolkata, was running around four to five hours late and was scheduled to reach city on December 26. The SBP-JAT Express from Sambalpur, Odisha, was delayed by about one hour, arriving at 2.53 am. The Vande Bharat Express arrived approximately 45 minutes late....