The mercury dropped at several places in the hills and the plains of north Bengal on Wednesday.

In the past 24 hours, Jalpaiguri, Raiganj and Cooch Behar have been colder, or the minimum temperature has been lower than Mangan in north Sikkim and Kalimpong in the hills.

In Darjeeling, the minimum temperature dropped to 1.4 degrees Celsius, while Jalpaiguri recorded a minimum of 7.5 degrees Celsius and Siliguri 8.8 degrees.

Officials of the India Meteorological Department (IMD) said such cold conditions were likely to persist for at least two to three days.

“There has been a layer of low cloud cover over most areas in the plains for the past few days, resulting in the cold day conditions, where even daytime temperatures remain low,” said Gopinath Raha, head of the IMD office in Gangtok.

“This situation will continue for the next two to three days. Also, dense fog will engulf major areas of the plains and the hills, further reducing daytime temperatures,” he added.

He pointed out that the minimum temperature recorded in Jalpaiguri is almost similar to Tadong (7.3 degrees Celsius) and colder than Mangan (8.1 degrees Celsius) in Sikkim, and even lower than Kalimpong (9.5 degrees Celsius).

The data show that Raiganj (9 degrees Celsius) and Cooch Behar (9.1 degrees Celsius) in the plains are colder than Kalimpong.

The minimum temperatures in Gangtok and some other parts of Sikkim, like Pakyong, Gyalsing, and Soreng, were almost the same — around five degrees Celsius.

Sources in the IMD have said that when the minimum temperature is 10 degrees Celsius or less in the plains and zero degrees or less in the hills, it is called the cold day condition.

The prevailing weather conditions have triggered snowfall in some parts of Sikkim. Mild snowfall was reported from higher altitudes of the Darjeeling district, leading to a further drop in temperatures.

Because of the cold spell, gloomy skies dominated most parts of north Bengal.

While temperatures in Siliguri and a few other areas witness marginal improvement during the daytime, cold day conditions are expected to persist in Malda, North Dinajpur and South Dinajpur districts.

Commenting on the weather in the plains of Darjeeling and Jalpaiguri, the IMD official said: “Such conditions are quite common during winter. There is a possibility that temperatures in the plains like Jalpaiguri may drop by another degree over the next couple of days.”

The Met office issued a forecast of dense fog and cold day conditions for Darjeeling, Jalpaiguri, Cooch Behar, and North Dinajpur and South Dinajpur districts until January 9. “As the western disturbance has moved away from the region, skies are expected to gradually clear. In Sikkim, there is a forecast of light rainfall or snowfall in Mangan and Pakyong districts,” said a source.