Around 300 people were stuck at their homes in Vasai town of the adjoining Palghar district due to waterlogging in the area.
The downpour -- the highest of the season so far in a day -- caused traffic jams as many roads and streets in Mumbai were flooded and people were seen wading through knee-deep water.
Vehicles on many roads were seen crawling because of rain and low visibility, while potholes compounded the problem.
The Mumbai University said examinations will be rescheduled for students who could not appear for it today.
The issue of heavy rains and its impact also figured in the Maharashtra Legislature's proceedings today.
Chief Minister Devendra Fadnavis told the Legislative Assembly that the inquiry would ascertain loopholes in arrangements for the monsoon session and whether problems were deliberately left unattended.
Nagpur is hosting the monsoon session of the state Legislature, but on Friday both the Assembly and the Council were adjourned for the day, shortly after convening, due to a power blackout caused by rains.
NCP leader Ajit Pawar sought to know at whose insistence the session was being held in Nagpur during rains, while Leader of Opposition in the state Assembly, Radhakrishna Vikhe Patil, said taxpayers' money was wasted since the day's proceedings of the House got washed out on July 6
Patil demanded that the chief minister apologise to the people of Nagpur for this.
Meanwhile, there was heavy water-logging in the central areas of Kurla, Sion and Dadar. Mira Road (in adjoining Thane district), and Nallasopara and Vasai (in Palghar district) were largely affected due to the heavy showers.
Train services of the Central Railway and Western Railway were slightly delayed due to water-logging on rail tracks in some places, officials said.
Some long-distance trains to Gujarat and northern states were halted at Borivali as tracks near Nallasopara and Virar were submerged. The trains left after a delay of about one hour, a spokesperson of the Western Railway said.
Brihanmumbai Electric Supply and Transport (BEST) buses were slightly delayed, but no service was cancelled or suspended, a BEST spokesperson said.
The city's neighbouring areas got even more rains, and roads were submerged.
Around 300 people were stranded at their homes in Meethanagar locality of Vasai as the road there was submerged.
"It is a low-lying area where water-logging occurs frequently," Palghar's district information officer said.
"The disaster management and Manikpur police station officials have established contact with the residents. A rescue team visited the area in a boat and we will continue to provide all help to the people," Palghar collector Prashant Nanavare told PTI.
The meteorological department has forecast more heavy rains in Mumbai till tomorrow.
"It is the highest rainfall of the season so far in 24 hours," IMD Mumbai's deputy director general K S Hosalikar said.
The observatory in suburban Santacruz recorded 122 mm showers during the same period, he said, adding, "The city and its suburban areas received a good spell of showers yesterday. Mumbai got a widespread downpour as the rain intensity escalated to very active."
Hosalikar said the intensity of rains in the city's neighbouring districts of Palghar, Raigad and some parts in the south Konkan region was even more "vigorous" with these areas receiving 200 mm rainfall since yesterday.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)