As per reports, dense fog enveloped Delhi-NCR on Sunday morning (19 January), causing disruptions to train schedules among other challenges;

• At least 41 trains were delayed, some by over three hours. Notable delays included the KIR-ASR Express, Lichchavi Express, Gorkhdham Express, Purushottam Express, Mahabodhi Express, Malwa Express, and Dakshin Express.
• According to the India Meteorological Department (IMD) at 0800 hours, dense fog conditions are very likely to continue during night/early morning hours in isolated pockets of Bihar and Odisha on Sunday (19 January); Punjab, Haryana, Chandigarh, Uttar Pradesh and West Rajasthan on Sunday and Monday (19-20 January); East Rajasthan during Sunday and Tuesday (19-21 January); Madhya Pradesh and Sub- Himalayan West Bengal and Sikkim till Monday (20 January); Assam, Meghalaya, Nagaland, Manipur, Mizoram and Tripura till Tuesday (21 January).
• Meanwhile the air quality in Delhi dropped to ‘very poor’ category on Sunday morning (19 January). Delhi’s overall Air Quality Index (AQI) stood at 335 at around 0700 hours, according to the Sameer app.