The southwest monsoon made a dramatic entry into Mumbai, dumping more than 200mm of rain across several parts of the city and suburbs, inundating low-lying areas, disrupting suburban train services and causing widespread inconvenience to commuters on Wednesday morning.
After days of anticipation the India meteorological department (IMD) officially declared the onset of the southwest monsoon over Mumbai on Tuesday, 13 days later than its normal arrival date of 10 June 2026. The monsoon's arrival was accompanied by intense overnight rainfall that left roads flooded and slowed transport services across the metropolis.
According to civic data, Mumbai recorded exceptionally heavy rainfall during the 24 hours ended 8am on Wednesday. The island city received an average of 195mm of rain, while the western suburbs recorded 208mm and the eastern suburbs 167mm.
In some locations, rainfall intensity was even higher. Data from the BrihanMumbai Municipal Corporation's (BMC) automatic weather stations showed that between 10pm on Tuesday and 6am on Wednesday, Malwani recorded 272mm of rainfall, followed by Powai with 248mm, Charkop with 244mm, Kandivali and Malad with 241mm each, Borivali with 237mm and Dadar and Vikhroli with about 210mm each.
Waterlogging Hits Key Areas
The heavy overnight downpour led to severe waterlogging in several low-lying areas, affecting vehicular movement during the morning rush hour.
Among the worst-affected locations were Andheri Subway, Hindmata Junction, King's Circle, Gandhi Market, Dadar and Malad subways, where rainwater accumulated rapidly. Traffic movement slowed considerably as motorists navigated flooded roads and congestion built up across major corridors.
Civic authorities deployed dewatering pumps at multiple locations to clear accumulated rainwater. Officials said the Andheri Subway was dewatered and reopened to traffic by around 5.30am.
Despite the heavy rainfall, the BMC said all major subways remained operational and traffic movement was largely manageable after water levels receded in several areas.
Railway Services Affected
The intense rainfall also affected Mumbai's suburban railway network, particularly services operated by Central Railway.
Commuters reported delays and overcrowding on local trains during peak morning hours as train movements were regulated due to water accumulation at certain locations.
The most significant disruption occurred on the Trans-Harbour line between Thane and Vashi/Panvel after a track cave-in was reported between Turbhe and Koparkhairane stations.
According to Central Railway officials, excessive water flow caused the cave-in, forcing authorities to declare the up line on the Thane-Vashi section unsafe at 5.06am. The down line was subsequently declared unsafe at 5.50am.
Restoration work was carried out on a war footing. Railway officials said the up line was restored at 7.27am with a speed restriction of 10kmph, while the down line was declared safe at 7.35am, allowing trains to operate at 30kmph.
Western Railway services, however, continued to operate normally despite the heavy rain.
IMD Issues Red and Orange Alerts
As rainfall intensified during the early hours of Wednesday, the IMD issued a red nowcast warning for Mumbai and Palghar districts at 4am, warning of thunderstorms, lightning, intense to very intense rainfall and gusty winds reaching 40-60kmph.
The warning was downgraded to an orange alert at 7am, though the weather department continued to caution residents about moderate to intense spells of rain across Mumbai, Thane, Palghar, Raigad and Sindhudurg districts.
IMD has forecast moderate to heavy showers accompanied by thunder and lightning in Mumbai and surrounding areas over the next 24 hours.
In a statement quoted by BMC, the weather department warned of "thunderstorms accompanied by lightning and intense to very intense spells of rain with gusty winds reaching 40-60kmph at isolated places." Authorities advised citizens to remain cautious and avoid venturing into waterlogged areas unless necessary.
High Tide Adds to Concerns
The heavy rainfall coincided with a high tide of 3.41 metres recorded at 8.28am on Wednesday. Another high tide of 3.35 metres is expected at 7.41pm.
Heavy rain during high-tide conditions often exacerbates flooding in Mumbai because stormwater drainage into the Arabian Sea becomes slower, increasing the risk of water accumulation in low-lying areas.
Civic and disaster-management teams remained on alert throughout the day to respond to any rain-related incidents.
Tree-Fall Incidents Reported
The adverse weather also led to tree-fall incidents in parts of the Mumbai Metropolitan Region.
In neighbouring Thane, a tree collapsed onto parked vehicles, damaging two cars and three two-wheelers. Fire brigade personnel and disaster-management teams reached the spot and removed the fallen tree.
A separate incident of a large tree falling on a car was reported near Dadar TT in Mumbai amid the intense rainfall.
Monsoon Advances Across Western and Central India
IMD said weather conditions remain favourable for further advancement of the southwest monsoon into remaining parts of Maharashtra, Gujarat, Madhya Pradesh and Chhattisgarh.
"The southwest monsoon has further progressed into the remaining parts of the central Arabian Sea, additional areas of Maharashtra including Mumbai, the remaining parts of Telangana and Odisha, and more regions of Chhattisgarh, Jharkhand and Bihar," the weather department said.
While the widespread rainfall has brought much-needed relief from the sweltering heat that prevailed across Mumbai in recent weeks, Wednesday's deluge also served as a reminder of the city's continuing vulnerability to flooding and transport disruptions during intense monsoon spells.
With IMD forecasting more rain over the coming days, authorities are expected to remain on high alert as the monsoon gathers momentum across Maharashtra.
