This January has so far been the warmest first month of the year in at least eight years.

The average maximum and minimum temperatures in January are 25.8 degrees and 14.1 degrees, respectively, according to the Met statistics compiled over the past three decades.

This year, the average maximum and minimum temperatures — from January 1 to 11 — have been 28.3 degrees and 16.3 degrees, respectively.

The average maximum temperature for both January 2017 and 2019 was 26.3 degrees, the most after this year. The average minimum temperature of January 2016 was 15.8 degrees, the most after 2021.

The Celsius is expected to slide again this week and drop below the 15-degree mark.

A Western Disturbance over north and northwestern India has stalled the flow of cold north-westerly winds, triggering a rise in temperature across the northern and central parts of India.

Since cold winds from Jammu and Kashmir reach south Bengal via these places — like Delhi and Uttar Pradesh — the temperature in Calcutta has been unusually high this January.

On Monday, the minimum temperature was 20.9 degrees, a whopping seven degrees above normal. The maximum temperature was 28.4 degrees, three notches above normal.

Woollens have already been kept back in cupboards. Even early mornings are warm. As the day progresses, fans are being switched on at many homes.

Normally, January 1 to 15 is the coldest period of the year. Over the past few years, there have been fluctuations and cold days have been interrupted by a brief warm spell or a couple of days of rise in temperature. But many Calcuttans could not recall the last time the fan had to be switched on for so many days in the first fortnight of January.

On four days this month, the Celsius has clocked 30 degrees.

The Met office has a word of hope though. “The Western Disturbance is dissipating while moving towards China. The Celsius in Delhi has started going down. Bihar and Jharkhand are expected to follow suit from Tuesday, paving the way for the cold winds to reach Calcutta,” said G.K. Das, the director of the India Meteorological Department, Calcutta.

The Celsius in Calcutta is tipped to go below 15 degrees from January 14, he said.

After a cold spell that characterised the end of December, the rise in mercury started from the first week of the new year.

A high-pressure system, positioned over parts of Bengal and Bihar on Sunday, has made the weather sweaty, said a Met official. “The system is drawing moisture-laden winds from the Bay. But the system has weakened and will dissipate in a day,” said the Met official.