The city was hot and humid for most of Tuesday.
The conditions in Kolkata and the rest of coastal south Bengal can become rainy from Friday, said a Met official.
On Tuesday afternoon, some areas on the southern fringes got rain. The rest of the city had to make do with only a cloudy sky.
The day's maximum temperature recorded in the Alipore Met office was 35.4 degrees, three notches above normal and almost same as the day before.
The minimum relative humidity, which was 61 per cent on Monday, dropped marginally to 59 per cent a day later. But it was still enough to make the conditions uncomfortable throughout the day.
"The monsoon trough now runs through Balasore in Odisha into central Bay of Bengal. A cyclonic circulation on the west-central Bay of Bengal has drawn the trough towards itself. There is a possibility of the circulation rising over the next 48 hours. If it comes close to the northwest Bay... coastal districts of Bengal will get rain," said G.K. Das, director, India Meteorological Department, Kolkata.