A heavy rainfall of 144 mm was recorded in the last 24 hours in the city, Regional Meteorological Centre Director G C Debnath told PTI.
But from today the rains will weaken and tomorrow onwards in will start decreasing further, he said.
The worst affected areas include Behala, Jadavpur, Belgachia, Rajarhat, Alipore body guard lines, Rashbehari Avenue, Thanthania, Golf Green, Tiljala, C R Avenue and College Street.
Traffic moved at a snail's pace adding to the woes of the office-goers as roads were flooded with ankle-deep water.
Kolkata Municipal Corporation's Member of Mayor-in-Council Tarak (Sewerage & Drainage) said rainwater is being pumped out with the help of 340 pumps at 73 pumping stations in various parts of the city.
"Besides this we are also using another 450 portable pumps to flush out all rainwater from the streets," he said.