The downpour led to waterlogging in parts of south and central Mumbai as well as eastern and western suburbs, leading to major traffic snarls in the morning peak hour.
Traffic crawled at a snail's pace on major thoroughfares like Eastern Express and Western Express highways and major north-south roads, delaying tens of thousands.
Suburban train services on Western Railway, Central Railway and Harbour Line ran 15-30 minutes late.
The Central Railway was hit due to flooded tracks near Sion-Kurla. The cascading effect affected the other two lines.
All domestic and international flights to and from Mumbai reported around 30 minutes delay due to heavy rains, low visibility and air congestion.
Besides Mumbai, the adjoining districts of Thane, Palghar and Raigad were also lashed by heavy rains, slowing traffic on all major routes linking Mumbai with Ahmedabad, Pune, Nashik and Goa.
The IMD has forecast very heavy rains over Mumbai and coastal Konkan region over the next 48 hours.
As a precaution, all major services like the police, fire brigade, NDRF and others are in a state of high alert.