Calcutta has been witnessing a cold spell since the last week with the minimum temperature plummeting to 11 degrees Celsius on January 8, but the mercury level is set to rise due to western disturbances, a Meteorological department official said.

The present cold weather condition in the eastern metropolis and its surroundings will continue for another 48 hours, and the minimum temperature will start rising from January 13, city-based Regional Meteorological Centre’s head Sanjib Bandyopadhyay said.

“In Bengal, we normally get cold winds from the north and northwest directions. For the last 5 days or so, the strength of such winds has been good,” he said on Tuesday evening.

During this period, there has neither been any western disturbance nor any systematic formation in the Bay of Bengal, keeping the temperature low, the official said.

“The minimum temperature will rise from January 13, owing to two western disturbances. It will rise all over the state, including the Gangasagar region where devotees will take a dip on January 15 on the occasion of Makar Sankranti,” he said.

A western disturbance is an extra-tropical storm originating in the Mediterranean region that brings sudden winter rain to the northern parts of the Indian subcontinent.