The city recorded the day's highest temperature of 40.2 degrees Celsius, regional Met director G C Debnath said.
"While parts of the city suffered from heatwave conditions, districts in western and southern Bengal suffered from severe heatwave conditions," he said.
Birbhum, Burdwan, Bankura, Purulia and West Midnapore districts recorded around 45 degrees Celsius or more during the day.
There was little hope for any respite from the severe heat tomorrow, he said.
Meanwhile, roads and public places were seen almost empty at noon in the metropolis and in other districts assailed by intense heat.