Alipore: Winds from the Bay of Bengal died down on Friday under the impact of a combination of factors, robbing Calcutta of rain.

As the humidity levels were high, Calcutta sweated throughout the day in the absence of the cooling effect of rain.

The weather department said similar conditions would prevail at least till Saturday, after which the flow of moisture-rich winds from the Bay might resume and rain is likely to return to the city.

The maximum temperature jumped almost two degrees in 24 hours to touch 33.4 degrees Celsius on Friday.

According to weather portal AccuWeather.com, the RealFeel was 40 degrees for three hours in the afternoon. The RealFeel, a measure of the effect of the weather on the skin when one is outdoors, is calculated taking into account parameters such as temperature, humidity, angle of the sun, and wind speed and direction.

"A well-marked low-pressure area that was hovering over Madhya Pradesh shifted towards Rajasthan on Friday, weakening the flow of moisture-laden air from the Bay. The system, after its west-ward movement, is drawing air from Arabian Sea, instead of the Bay of Bengal. That is why clouds vanished from the Calcutta skies and the sun shone brightly," said Sanjib Bandyopadhyay, deputy director general, India Meteorological Department, Calcutta.

Some moisture would still have flowed in from the Bay but for two cyclones over the South China Sea, which were pulling the winds away.

The monsoon trough, an imaginary line joining the low-pressure points across the breadth of the county, is passing through Chandbali in Odisha, more than 350km to the south of Calcutta. Rainfall tends to concentrate around the places through which the monsoon trough passes.

"The sun was beating down hard on Friday because the city skies were free of clouds. Radiation reflected off the surface of the earth and absorbed by the lower atmosphere was pushing up the temperature," an official in the Met department said.

"The air is always heavy with moisture during the monsoon. Heat and humidity both were high in the afternoon. The human body tries to lose heat by sweating. When sweat evaporates it leaves behind a cool feeling. But when humidity is high, this mechanism fails as the sweat lingers on the skin," the official explained.

The situation could change around Sunday when a low-pressure area is likely to form over the north Bay of Bengal.

"The last two low-pressure areas over the Bay of Bengal had formed near the Odisha coast. But this one is likely to take shape over the north Bay, closer to the Bengal coast. That is why Calcutta and its surroundings could get more rain from Sunday than it has got over the past 15 days or so," said Bandyopadhyay.