Car windows rolled up at night: Yes
Fan at full pelt: No
The past few days have re-ignited Calcutta’s hypersensitivity with winter — the stuff of the legendary monkey-cap humour. The slight nip in the night air, though, is not a sign of early winter, Met officials said.
The minimum temperature has been around 22 degrees for the past three days. On Tuesday, the Celsius plunged to 21.3 degrees, a notch below normal.
The moisture content in the air has come down and cold winds from northwest India have been blowing in for around two days.
“There is no system nearby that can lead to overcast conditions in Calcutta. As a result, the moisture content in the air has gone down. The absence of moisture has allowed free flow of winds from the north, via Bihar,” said G.K. Das, the director of India Meteorological Department, Calcutta.
The forecast for the next few days is clear sky during the day and a nip in the night air, Das added.
But he clarified that the “cool phase” was not the start of the city’s fleeting winter, which is usually declared in the second week of December, when the minimum temperature remains 16 degrees Celsius or lower for a few days at a stretch.
The dry winds from north had started blowing after a post-Puja wet spell sucked in moisture in the air. But a low-pressure area near the Andhra coast made the run-up to Diwali wet in Calcutta and elsewhere.
The moisture level in the air kept rising and the city got persistent rain on Thursday and Friday. But the sky later cleared and Diwali was rain free.
Moisture-rich air blocks winds from the north or northwest, resulting in a rise in the temperature.
“For the temperature to stay low, the atmosphere needs to discard the heat that accumulates during the day. Heat finds a vent when the sky is clear. If it doesn’t, nights would feel stuffy with the trapped heat being carried over to the next day, just like the weather had been in Calcutta before the showers,” a weather scientist said.
The minimum relative humidity, hovering above 90s on October 24 and 25, has since gone down. It was 56 per cent on Monday and Tuesday.
