Winter temperatures in Calcutta climbed above normal for the first time in 10 days on Tuesday and set the tone for a relatively warm week.

The minimum temperature rose from 15.4 degrees Celsius, a degree below normal, on Monday to 16.8 degrees Celsius, a degree above normal, a day later because of a cyclonic circulation over the Bay of Bengal and “weak flow” of northwesterlies, the weatherman said.

The good news is that this isn’t another spell of freak weather in a city that has already faced three unusually warm phases, the last one being the fortnight leading to the earliest winter in five years.

“It is not abnormal for temperatures to rise by a degree or two above normal during this phase. These conditions are likely to prevail for another four days or so,” said Gokul Chandra Debnath, the director of the Regional Meteorological Centre in Alipore.

So when will the mercury dip again?

“We don’t expect temperatures to dip before at least the weekend or early next week,” Debnath said.

Doctors warned of illnesses if temperatures fluctuated by several degrees over the next few days.

“A sudden rise in temperature increases one’s vulnerability to cold, cough and fever. Asthma, chronic obstructive pulmonary disease and other respiratory illnesses could get aggravated,” said critical care specialist Subrata Maitra.

His word of caution? Don’t drink chilled water or go in for a cold shower “even if the weather continues to be warm”.