The Kolkata Traffic Police on Sunday issued a fog alert for the city, warning motorists of low visibility during the early hours of 23 and 24 December.
Citing an India Meteorological Department forecast, the advisory said foggy mornings could increase the risk of road accidents and urged commuters to drive cautiously.
The traffic police advised drivers to slow down, use headlights and fog lamps, maintain a safe distance from other vehicles and avoid overtaking.
The alert comes amid a wider fog warning issued by the India Meteorological Department.
The weather agency said dense to very dense fog is likely to prevail during morning and night hours in eastern Uttar Pradesh, Punjab, Haryana, west Uttar Pradesh and northern Madhya Pradesh on Monday.
According to the IMD, Bihar, Jharkhand and interior Odisha are also likely to experience dense fog conditions till 24 December, raising concerns over visibility on highways and urban roads across eastern and northern India.
In Kolkata, temperatures are expected to hover between the mid-teens and mid-20s Celsius over the next two days, with misty mornings giving way to clearer skies later in the day.
Authorities have urged commuters, especially early-morning travellers, to remain alert and follow traffic advisories as fog conditions persist.