Republic Day weekend: IMD warns of dense fog, renewed cold wave as another western disturbance lines up

India’s Republic Day weekend is shaping up to be a test of winter resilience, with the India Meteorological Department (IMD) warning that dense to very dense fog could reduce visibility across parts of Punjab, Haryana and Rajasthan as temperatures slide again after recent showers.

The outlook follows a brief spell in which rain and strong winds improved conditions in some cities. In Delhi, the Air Quality Index (AQI) dropped to a “moderate” reading after rain and gusty winds, even as forecasters cautioned that the improvement may be short-lived and pollution levels could rise again as weather turns more stable. The same systems that cleared the air also pushed down minimum temperatures, setting the stage for colder nights through the weekend.

Weather agencies are also tracking a fresh western disturbance expected from January 26, which could bring another round of light to moderate rain in parts of north India and raise the risk of thunderstorms, lightning and gusty winds in some pockets. The combination of moisture, low temperatures and calm spells at night is likely to intensify fog formation in the late night and early morning hours—timing that can hit highways, rail corridors and flight schedules hardest.

For commuters, the key risk is visibility. Dense fog can force slower speeds on expressways, disrupt train movement and trigger flight delays during the morning peak. Authorities have urged travellers to check advisories, allow extra time, and use fog lights and safe following distances when driving.

Residents are also being advised to prepare for a colder, damp feel in the morning air—especially in the Indo-Gangetic plains—where humidity lingers after rain. Vulnerable groups such as the elderly, very young children and people with respiratory illness are typically advised to minimise exposure to cold, wear layered clothing, and avoid early-morning outdoor exertion in foggy conditions.