The downpour began on Tuesday and continued until Wednesday. The Patenga weather office has recorded 98.8 mm of rainfall until Wednesday noon.
Office-goers and students faced difficulties after leaving homes in the morning as few vehicles took to the streets due to the rain.
The number of vehicles increased as the day progressed, and so did the intensity of the rains.
"The port city's DC Road was waterlogged last month as well. The heat has been intense so far," said Saiful Alam, a local resident.
"The road in the area got waterlogged as soon as the rain started on Wednesday. It was difficult to take my children to school."
Rainwater flooded the city's 2 No. Gate, Chawkbazar Kitchen Market, Chandgaon, CDA Residential Area, parts of Agrabad and Bakalia, DC Road, Wapda area in Halishahar, Chattogram Maa-O-Shishu Hospital area in Agrabad, Badurtola, Sulakbahar and Muradpur.
"On other days, transports run empty at this time, but the number of vehicles is fewer than usual today," said Toriqul Alam, who was soaked in the rains as he waited for a ride to the New Market area.
But the showers were a cause for celebration for many residents after enduring two weeks of searing heat. Some went outdoors and got drenched in the rain, while others jumped into lakes to enjoy the downpour.
"The rains triggered by the monsoon winds will continue for several days. The day and night temperature may fall slightly across the country," said Bishwajit Chowdhury, forecast officer at the Patenga Met Office.