The maximum temperature touched 40 degrees Celsius - four notches above normal - on Thursday.
The weatherman has forecast that it would remain like this at least for the next three days.
The temperature, according to AccuWeather.com, read 38 degrees Celsius at noon but the RealFeel was 53 degrees. The humidity around that time was 51 per cent.
RealFeel indicates the impact of heat and humidity on the skin under the sun.
On Thursday, it felt uncomfortable even at 11am as hot dry winds from central parts of the country kept blowing into the city.
"The temperature will be in the 40-degree range and there is no possibility of thundershowers," a Met official said.
Both heat and humidity are required for the formation of thunderclouds.
But at the moment there is only heat in the Chhotanagpur Plateau, the Nor'wester hatchery, the official said.
The heatwave has ended in the city but it continues to sweep the districts of Burdwan, Bankura, Purulia and West Midnapore.
Heatwave is marked by a maximum temperature above 40 degrees Celsius and 4.5 degrees or more above normal.
The maximum temperature was above 40 degrees Celsius between Sunday and Tuesday.
The government had on Saturday announced that state-aided and state-run schools would remain closed from Monday till further notice.
The soaring temperature has forced many private schools to close early, especially for junior sections.
A weather scientist said the high temperature was the result of a trough of low pressure in North Bengal, which is drawing moisture from the Bay of Bengal.
Such a trough is often found in the vicinity of Calcutta during summer, which is why there is a steady flow of moisture into the city.
A trough of low pressure has atmospheric pressure lesser than its surroundings, so it draws air towards itself.
There is often a high-pressure belt along the Bengal-Odisha coast, which is deeper south in the Bay of Bengal this time, the Met official said.
"Hot winds flowing unhindered from central India is pushing up the temperature in the city," he said.
