Sunday was dark, damp, dreary and unusually cold in Kolkata.
In ways more than one, Sunday felt almost like an encore of Thursday — uniformly sunless and gloomy. The only difference was that Sunday saw only traces of rain in some areas while Thursday had seen multiple spells of light rain in and around the city.
The overcast conditions dragged the maximum temperature down to 19.6 degrees, six notches below what is considered normal in the third week of January. On Thursday, it was 19.2 degrees.
The minimum temperature was 15.2 degrees Celsius on Sunday, a notch above normal. Thursday's minimum was 16.3 degrees.
“For most part of Sunday, the temperature was around 17 degrees in Kolkata. That is why it felt so cold,” said a Met official.
The low day temperature was the main reason for the chill. The minimum temperature is recorded in the early hours of the day, usually just before sunrise, when most in the city sleep. The effect lingers on for a while.
But the effect of the maximum temperature — which is recorded in the afternoon, usually when the sun is directly overhead — is felt for a large duration of the day.
“A dense layer of fog is extending from over Delhi and Punjab to Gangetic Bengal. The layer descended, riding strong northwesterly winds, about a week ago. Now, since the northwesterly winds have weakened, there is no mechanism to lift the fog,” said G.K. Das, director, India Meteorological Department, Kolkata.
“In addition to the fog, there is an anti-cyclonic circulation (a high-pressure zone) on the Bay of Bengal. Moisture-laden winds are coming from the Bay to comparatively low-pressure zones in Odisha, East and West Midnapore, South-24 Parganas, and also to Kolkata,” he said.
The moisture is leading to the formation of clouds closer to the surface of the earth. The fog and clouds are together shielding the sun.
The Met office sees little change in the conditions till January 25.
"The maximum temperature is likely to range between 19 and 21 degrees, which means the days will be cold. The sun might come out but only in phases. The sky will be generally gloomy. Some rain is expected in Kolkata around January 23-24," said Das.
From January 26, the system over the Bay is tipped to weaken and the northwesterly winds are likely to pick up steam.
The days are then going to be sunnier and the fog will start dissipating, Das said. The maximum temperature will rise but the minimum will fall.