Early birds, all wrapped up, out in the fog over the Maidan. Picture by Amit Datta

The Met office on Tuesday said chilly days were ahead, following a cold wave in the country?s northern regions.

The minimum temperature, that hovered over 17 degrees last Thursday and Friday, dropped to 13.6 degrees Celsius on Monday.

Met officers said the minimum temperature again rose to 15.5 degrees on Tuesday because of a heavy incursion of moisture from the Bay of Bengal, following development of a trough of low pressure in the upper atmosphere along the coast between Gangetic West Bengal and Andhra Pradesh.

This low pressure led to a cloud cover over Calcutta and its adjoining areas and could lead to light rain in isolated areas. Weather officers, however, said Tuesday?s phenomenon is temporary and chilly days are expected after about 48 hours.

?This is a temporary phenomenon and we expect the system to clear by Wednesday. Then, we expect the minimum temperature to dip again,? said G.C. Debnath, director of weather section at the Regional Meteorological Centre in Alipore.

Debnath said even though Monday?s minimum temperature was lower, Tuesday felt cooler because of the flow of wind from the north in the lower level and a mild sun.

?The day was cloudy for most of Tuesday and there was very little sun to heat the surface. The cold wind from the north, blowing at about 15 kph, gave a chilly feel,? said Debnath.

?According to reports on Tuesday evening, a cold wave condition is prevailing in Punjab and Haryana. If the sky clears tomorrow, we expect this chill from north India to carry to Calcutta,? he added.