The days are set to get warmer from Monday, the Met office has said.
The usual daily maximum temperature now is around 35 degrees Celsius. In the past couple of days the maximum was lower than that. But the mercury rose sharply on Sunday and Monday would be even warmer, according to the Met forecast.
The maximum temperature on Saturday was 27.3 degrees Celsius, a staggering eight notches below normal. The minimum was 22 degrees, three notches below normal.
On Sunday, the maximum rose five degrees to 32.3. It was still significantly lower than the usual.
In parts, the day was hot but there were occasional clouds. The heat was not blistering.
A north-south trough of low pressure passing over West Bengal, resultant moisture flow from the Bay of Bengal and sufficient heating had combined to trigger overcast conditions in Kolkata on Thursday.
The city received a sharp spell of thundershowers on Thursday night. Friday and Saturday also saw sporadic rain in some parts of the city.
"But the trough has changed position now. In the next few days, there are very slim chances of the trough affecting Kolkata," said a Met official.
"As a result, the days will be warmer. The discomfort index is also set to rise gradually as the moisture content in the air goes up."
The average daily maximum temperature in early April is around 35 degrees, he said.
"In the coming days, that mark is likely to be breached," he said.
Monday's maximum, according to the forecast, will be around 34 degrees.
The start of summer has been rainy this year.
In 2022, the city had just a single squall and not a single Nor’wester in entire April, making the start of summer uncomfortably hot. But the start of May was reasonably wet.