The Indian Meteorological Department, meanwhile, warned of intense spell of 30 to 50 mm rainfall per hour with strong winds in Mumbai and suburban areas.
Schools and colleges in the city and adjoining districts have been closed as a precautionary measure.
As incessant rains lashed Mumbai and Maharashtra, life was thrown out of gear with delay in train and flight services causing great inconvenience to passengers.
the Indian Meteorological Department's Mumbai observatory had issued a warning for rain and thundershowers in the city and suburbs beginning from Monday night owing to the cyclonic storm Ockhi which is 670 km south west of Mumbai
The WR is taking various measures including setting up disaster management rooms, help desks, and keeping relief trains ready.
Chief Minister Vijay Rupani said people living in the coastal belt would be shifted to safer places.
Mumbai recorded over 250 mm of rain in just three hours (between midnight and 3 am), touching 305 mm by 7 am on Sunday, a meteorologist said.
According to the India Meteorological Department (IMD), the Ayanagar weather station recorded 99.2 mm rainfall, the maximum in the city, during the 24-hour period ending at 8.30 am on Thursday.
Heavy rains over a span of few hours flooded many parts of Nagpur city, following which more than 400 people, including 70 students from a school for the speech and hearing-impaired, were rescued, said Maharashtra Deputy Chief Minister Devendra Fadnavis on Saturday.
According to disaster management control room of the civic body, no injury or casualty has been reported so far.
Incessant rains since the wee hours of Friday threw normal life out of gear in Mumbai
Over 20,000 people were evacuated to safer places in these three districts. State capital Mumbai too witnessed water-logging in many areas after overnight rains on Thursday.
Heavy rains lashing Mumbai since Sunday have thrown rail, air and road traffic out of gear, with several trains and flights being cancelled. With IMD forecast of heavy rains for Tuesday, the authorities declared a holiday in the city and adjoining regions, asking people to avoid stepping out of their houses.
'Already, the temperature has touched 39 degrees in some parts of Gujarat and now we are in the last week of February.' 'We need to activate the heat action plan from March 1.'
With the cyclone set to make landfall on Wednesday, Maharashtra and Gujarat activated their disaster response mechanism, deploying NDRF teams and evacuating people from areas likely to be hit.
Mumbai received 231.4 mm rain in the last 24 hours, while Thane received 229.81 mm.
The DG said the maximum of four teams of the NDRF have been positioned in Kutch district and the Gujarat government has done an in-depth evacuation exercise as part of which fishing boats have been anchored, big ships have been sent to the high seas so that they are not affected by the tidal waves, more than 4,000 hoarding have been taken down so that they don't become deadly flying objects as strong winds blow.
Gale-force winds, heavy rainfall and high tidal waves swept the coastal belt of Kerala, Karnataka and Goa as Cyclone Tauktae hurtled northwards towards Gujarat on Sunday, leaving four people dead in Karnataka and two in Goa, damaging hundreds of houses, uprooting electricity poles and trees and forcing evacuation.
Incessant showers caused landslides and floods in various parts of the country leaving at least 17 people dead on Wednesday while thousands more were forced to move to safety as rivers swelled and water reservoirs filled up fast.
Delhi's primary weather station, the Safdarjung Observatory, registered a maximum temperature of 40.4 degrees Celsius, four notches higher than normal.
The two western states, already battling a raging pandemic, which has put their health infrastructure under severe strain, opened new fronts to tackle the fallout of the storm which is expected to make a landfall close to Mumbai on Wednesday. They are likely to be impacted most by the cyclone.
Thackeray is in constant touch with collectors of districts on the western coast of the state for updates about the impact of Nisarga, the Chief Minister's Office (CMO) said.
Isolated heavy rainfall is also very likely over north Konkan region during the same period, it said.
The landfall process started around 12.30 pm. It made landfall about 40 km from Alibaug, 95 km from Mumbai.
A cyclone alert has been sounded across north Maharashtra and south Gujarat, besides coastal areas, by the Meteorological Department, in the wake of a deep depression over the Arabian Sea.The bulletin said the deep depression (system) is likely to intensify further into a cyclonic storm.The Met office has advised fishermen not to venture out to sea in Kerala, Karnataka, Goa, Maharashtra and Gujarat.It warned that Mumbai and Thane districts will receive very heavy rains.
Flight operations at the Mumbai airport were suspended for nearly half an hour as visibility dropped well below the required 550 meter-mark
the India Meteorological Department has forecast intermittent rain with heavy to very heavy showers in the city and suburbs and extremely heavy rain at isolated places in next 24 hours.
Private weather agency Skymet said Mumbai is at 'serious risk of flooding' between July 3 and 5.
An NDRF team has a strength of about 45 personnel and each unit is equipped with tree and pole cutters, communication gadgets, inflatable boats and a small basic medical unit.
The India Meteorological Department (IMD) has forecast 'extremely heavy rains' at a few places in Marathwada, Mumbai and other parts of the coastal Konkan region of Maharashtra in the next 24 hours.
No immediate relief appears in sight as the India Meteorological Department issued a red alert for six districts which have been already pounded by downpour, forecasting "extremely heavy" rainfall and recommending preventive actions.
Though the "eye of the storm" is away from land, the cyclone's outer periphery would leave its impact on the coast.
The maximum death toll has been reported from Idukki district, where 43 people have lost their lives so far, as per official estimates. 28 deaths were reported in Malappuram and 27 in Thrissur.
The deep depression in the Arabian Sea has intensified into cyclonic storm "Ashobaa" and is expected to further develop into a "super cyclonic storm" in next 24-36 hours, the weather office said on Monday.
