Dark clouds gathered over the city on Thursday afternoon but the rain that followed was scattered.
Parts of central Kolkata and Howrah received a spell of rain. South Kolkata was mostly dry.
The Met office recorded around 2mm of rain in Alipore. But most parts of the city were breezy for a brief while after 3.30pm.
“The clouds formed locally. They were not strong enough to trigger uniform thunderstorm activities,” said a Met official.
Around 4pm, the sky was grey over the Rabindra Sarobar in south Kolkata. Rowing in the lake has been on hold since two teenage rowers drowned during a fierce storm last Saturday.
The maximum temperature rose to 37.2 degrees on Thursday, two notches above normal.
Thunderstorms are possible almost every alternate day, according to the Met forecast.
“There is a cyclonic circulation over Bihar. A trough of low pressure exists from Rajasthan to Odisha. The moisture incursion because of these two systems is triggering the formation of thunderclouds,” said the Met official.
Met officials remained non-committal about the onset of the monsoon.
The usual date of the onset in north Bengal is June 5. For south Bengal, it’s June 8.
“The monsoon is on track to reach Kerala on June 1,” said the official.