Dry weather is expected over the rest of the country during the next four to five days.
Western Maharashtra and coastal districts have been receiving heavy rains since Wednesday resulting in damage to property and lives.
The island city received 106.01 mm rain in the 24-hour period ending at 8 am on Thursday, followed by 69.18 mm rain in eastern suburbs and 58.36 mm in western suburbs during the same period, a Brihanmumbai Municipal Corporation (BMC) official said.
Overall, the country has received 9 percent more rainfall than normal until September 26, according to data.
The northwest meteorological division of IMD comprises Rajasthan, Uttar Pradesh, Himachal Pradesh, Uttarakhand, Punjab, Haryana and the Union territories of Chandigarh, Delhi, Jammu and Kashmir and Ladakh. Almost all states have recorded a large deficiency from September 1-23.
IMD rain forecast Mumbai: An orange alert has been issued and IMD expects intensity of rainfall in Mumbai and Thane to decrease from September 23.
Several parts of central and south India are likely to receive heavy rainfall in the next two days. The IMD has also issued orange warning for Kerala, Goa and parts of Karnataka and Maharashtra on Saturday.
The IMD defines average, or normal, rainfall as between 96 percent and 104 percent of a 50-year average of 88 cm for the entire four-month season beginning in June.
The overall rainfall recorded in India from June 1 to August 31 was 10 percent more than normal, the IMD said on Monday.
The country has received the highest rainfall in the month of August in the last 44 years, according to data of the India Meteorological Department (IMD), which has issued a red alert forecasting more extremely heavy rains in many areas of Madhya Pradesh.
The India Meteorological Department (IMD) data shows that in August 1976, the country had recorded a 28.4-percent excess rainfall.
IMD said a low pressure area (cyclonic circulation) over north Bay of Bengal and its neighbourhood is very likely to move west-northwestwards during the next four-five days.
Of the 36 meteorological subdivisions in India, monsoon rains have been either average or above average in 32 so far this year, Mrutyunjay Mohapatra, director general of the IMD said.
The orange alert implies that authorities should be ready to handle situations arising out of severe weather.
Isolated places in Mumbai are likely to receive heavy rains, while neighbouring districts of Thane, Raigad and Ratnagiri will witness more intense showers for the next 24 hours, the official said.
Heavy rainfall is likely at some places in the Western Ghat sections of Madhya (central) Maharashtra and coastal region of the state starting Sunday, the official said.
An IMD official on Monday said the "extremely heavy" forecast means Mumbai, Raigad, Thane, Pune and Ratnagiri may get more than 204.5 millimetres of rain in a period of 24 hours.
The intensity and distribution of rainfall is very likely to increase over sub-Himalayan West Bengal, Assam, Meghalaya and Arunachal Pradesh with widespread rainfall activity along with isolated heavy to extremely heavy rainfall during July 26-29.
The convergence of moist easterly winds from the Bay of Bengal and southwesterly winds from the Arabian Sea is likely to continue over northwest India for another two-three days, weather experts said.
"Increased rainfall activity expected for next three-to-five days along the coastal areas," IMD said.
The orange alert by the IMD's Mumbai centre is also for coastal districts like Raigad, Ratnagiri, Sindhudurg as well as Pune in western Maharashtra.
According to India Meteorological Department's Mumbai centre, the Colaba weather bureau reported 161.4 mm rainfall between 8:30 am and 8:30 pm on Friday.
A good start to the June-September monsoon season has accelerated planting of summer-sown crops, with farmers sowing crops on 31.56 million hectares as of June 26, doubling from 2019, when the monsoon arrived late.
The monsoon usually sets over Kerala on June 1 and it takes 45 days to reach Sriganganagar in west Rajasthan, its last outpost in the country.
The IMD has predicted normal rainfall (103 per cent) for northwest India this year.