There appears to be no respite coming anytime soon for cold-hit north India as severe weather conditions continue to disrupt day-to-day life in the region.Many places in the region saw single-digit temperatures and dense fog in January 18 morning hours. From several states, there were reports of low visibility severely affecting commuters.Very dense fog kept parts of Punjab, Haryana, West Rajasthan and Bihar enveloped, a Met department bulletin said.Similar heavy fog was also reported in isolated parts of Delhi, West Uttar Pradesh, Jharkhand, Odisha and Assam. Moderate fog was observed in isolated parts of Sub-Himalayan West Bengal and Sikkim, the IMD added.Hit by thick fog, Northern Railways reported delays for 18 trains. Among them, the Bhubneshwar-New Delhi Rajdhani Express, Ambedkarnagar-Katra, and Muzaffarpur-Anandvihar were delayed by approximately 3-3.45 hours.The Puri-Nizamuddin Purushottam Express was expected to arrive six hours later due to fog. The Rewa-Anand Vihar Express and Azamgarh-Delhi Junction Kaifiyat Express were also seeing delays of around 4.30 and 5.30 hours, respectively.Nine more trains were running behind by 1-1.15 hours, as per Railways’ morning-hour updates. These trains include Jammutawi-New Delhi Rajdhani Express, Banglore-Nizamuddin Rajdhani Express, Pratapgarh MLDP-Delhi, Dehradun-Delhi Junction, Chennai-New Delhi Express, Ferozpur-Mumbai Express, Amritsar-Mumbai Express, Kamakhya-Delhi Junction, and Jammutawi-Ajmer Pooja Express.Poor visibility in the wake of fog also disrupted flight services, causing delays and cancellations. Passengers faced inconvenience at airports, with many stranded.Flights at the Indira Gandhi International Airport saw large-scale disruptions due to poor visibility. At the airport, visibility was reported between 50 and 100 meters from 12 am to 6.30 am. By 8 am, visibility had improved a bit at 300 meters, the IMD reported.The IMD forecast dense to very dense fog for a few hours late night and morning over parts of Punjab, Haryana and Chandigarh between January 18 and 20.Minimum temperatures could go up by about 2 degrees in Northwest India over the next 24 hours, the IMD said. There will, however, be no significant change thereafter, it added.