The Met office is spying cooler nights and days over the next day or two as the mercury is likely to drop by 2 to 3 degrees Celsius, a weather scientist said on Saturday.
There is a possibility of rain on Tuesday or Wednesday, said the weatherman.
But a real nip in the air is unlikely before the third week of November.
The city is reeling under higher-than-normal temperatures.
The maximum temperature recorded on Friday was 32.2 degrees Celsius, 1.3 degrees above normal. The minimum temperature was 26.2 degrees Celsius, 3.6 degrees above normal.
On Thursday, the maximum temperature was 32 degrees Celsius, 1.1 degrees above normal. The minimum temperature was 26.9 degrees, 4.3 degrees above normal.
"The maximum and minimum temperatures in Calcutta and neighbouring areas are likely to drop by 2 to 3 degrees in the next two days," said Mani Sankar Jana, scientific officer-I at the India Meteorological Department, Calcutta.
"This drop will be because of dry and cooler westerly winds coming into the city and neighbouring areas," he added. The day and night on Diwali (Thursday) and the day after (Friday) have been warm, forcing many to cool off in their rooms after spells of bursting firecrackers.
Many Calcuttans said they are using their air-conditioners through the night even now.
"But the nip that comes with an approaching winter is likely only after the second week of November gets over. The nip in the air is felt only when the minimum temperature drops below 20 degrees Celsius and the maximum temperature goes down below 30 degrees," said Jana.
He added that historical data reveals that the mercury goes down below 20 degrees only after the second week of November.
This nip can appear a week in advance in the western districts of Bengal, he said.
Jana said that there is a possibility of rain in Calcutta over the middle of next week.
"Rain is likely on November 5 or 6. This will be a result of a combination of dry westerly winds and moisture-laden winds from the coast coming in," he said.
There is a forecast of rain for North and South 24-Parganas, and East Midnapore also.
