Cold air from the north is expected to return to Bengal starting Sunday, leading to a drop of 3 to 4 degree Celsius in the minimum temperature by Tuesday, said the weather office on Saturday.

The minimum temperature in Kolkata is currently 4 degree Celsius above normal. On Friday, Kolkata recorded a minimum temperature of 18.2 degree Celsius and a maximum of 26.5 degree Celsius.

Meanwhile, flight operations at Kolkata airport were disrupted Saturday morning due to the implementation of Safeguarding Procedures owing to dense fog conditions. Twenty-three arrival flights and 30 departure flights experienced delays in the first half. However, no flights were diverted during this period.

A dense fog warning has been issued for four districts in South Bengal and four in North Bengal for three days starting Sunday. Visibility may drop to around 50 meters in some areas, said weather experts.

The weather office has also predicted light rain in Darjeeling, Kalimpong, and Jalpaiguri in the next 24 hours.