Cyclone Nisarga made landfall on the Maharashtra coast at around 1 pm amid heavy rain and the process will be completed in three hours, the India Meteorological Department (IMD) said.
Severe cyclonic storm Nisarga is the second to strike India in less than two weeks after the powerful cyclone "Amphan" created havoc in West Bengal and Odisha.
Thousands of residents were evacuated from along the coasts of Maharashtra and Gujarat, which are also the worst-hit states by the coronavirus pandemic.
The Indian Navy and teams of the National Disaster Response Force (NDRF) were on standby to conduct rescue and relief operations.
Maharashtra state, of which Mumbai is the capital, and neighbouring Gujarat have evacuated at least 1,00,000 people to safer locations. The fishermen have been advised not to venture out in sea until the storm passes.
Cyclone Nisarga is the first such storm to hit Mumbai in nearly 100 years
A family look for shelter during rainfall ahead of Cyclone Nisarga's expected landfall, in Navi Mumbai (PTI)
Around 1500 citizens evacuated in the view of the Cyclone Nisarga (PTI)
Commuters brave rainfall at Bandra ahead of Cyclone Nisarga's expected landfall, in Mumbai (PTI)