Saturday morning began cool, but the day turned summery within a few hours.
In many homes, ceiling fans whirred for the first time this season, while car coolers were put to use as temperatures rose through the day.
The Met office said there was a gap of more than 12° Celsius between the temperatures recorded early on Saturday morning and those in the afternoon. No major change in conditions was likely in the next five to six days, it said.
According to the IMD, western disturbances have taken the chill out of the city. “Successive western disturbances are stalling the winds that could have made the days colder,” an IMD official said.
How cold Calcutta gets during winter depends largely on the flow of northwesterly winds. But these winds are not getting free access to south Bengal. “There was a western disturbance earlier that led to snowfall in north India. Another one has formed now,” the official said.
Seasonal factors are also a reason. “Days are getting longer and the sun is shining bright. Under their impact, the earth’s surface is heating up. The day temperature is 25° to 26°,” the official said.
The wide gap between the minimum and the maximum temperatures is making the days feel warmer.
“Both maximum and minimum temperatures are in the normal range,” the official said. “This winter was the coldest in a long time, and the return of normal day temperatures this week is creating the impression of hot weather.”