The chill has gone missing from Kolkata.
On Sunday, the minimum temperature was 16.7 degrees Celsius, three notches above normal. It was tipped to breach the 17-degree mark on Monday.
Keeping an additional layer of warm clothing has become challenging in the day. The winds that had been dragging the Celsius down have disappeared.
A Met official blamed the weather conditions in northern parts of India for the warm spell in Kolkata. The spell is likely to persist at least till January 10, according to the Met forecast.
There is a possibility of a gradual slide in the Celsius after January 10, said a Met official.
"Swathes of the northern parts of the country are engulfed in a dense blanket of fog. Under the impact of one Western Disturbance after another, a weather system is always in the works in north India. As a result, the northwesterly winds from Kashmir, the usual agents of chill, are stalled. They cannot get a passage to south Bengal," said G.K. Das, director, India Meteorological Department, Kolkata.
A cyclonic circulation now lies over west Uttar Pradesh.
The layer of fog extends up to Bihar and parts of Malda. But it is enough to block the northwesterly winds, said Das.
Places like Delhi and Punjab are experiencing the bite of the chill despite the fog impairing the usual flow of the northwesterly winds there as well.
"That is largely because the fog is not allowing the sun to shine brightly. The days have been much colder than usual in north India. As a result, the maximum temperature is on the lower side," said Das.
The IMD website said: "Maximum temperatures are in the range of 9-12°C over many parts of Punjab and Haryana; in the range of 13-16 °C over north Rajasthan, Delhi, northwest Madhya Pradesh and some parts of Uttar Pradesh. It is below normal by 4-9°C over these areas".
"The minimum temperatures are in the range of 6-9°C over Rajasthan, Punjab, Haryana-Chandigarh-Delhi; 10-12 °C over parts of west Uttar Pradesh and northwest Madhya Pradesh. It is above normal by 1-3°C," it said.
A bulletin issued on Sunday by the IMD headquarters in Delhi said: "Cold day to severe cold day conditions are likely to continue over Punjab, Haryana, Chandigarh, Delhi and Rajasthan during next two days and decrease thereafter. Dense to very dense fog likely to continue over northwest India during next two days and gradually decrease thereafter."
A fresh spell of rain with thunderstorm/hailstorm is also likely over Rajasthan and adjoining northwest India between January 8 and 10, the note said.
Das of the Met office in Alipore said the minimum temperature in Kolkata is unlikely to drop below 15 degrees before January.
"After January 10, if the fog starts thinning and the impact of the Western Disturbance is gone, northwesterly winds may start entering Kolkata again," he said.