Mumbai experienced the onset of the southwest monsoon on Tuesday, June 23, 2026, 13 days after its normal arrival date of June 10. The city recorded over 200 mm of rainfall in the 24 hours ending at 8 am on Wednesday, leading to widespread waterlogging, traffic congestion, and suburban train service disruptions.
Rainfall Data and Impact on Low-Lying Areas
According to civic data, the island city recorded an average of 195 mm of rain, while the western suburbs received 208 mm and the eastern suburbs 167 mm. The downpour inundated low-lying areas such as Andheri subway, Hindmata, and King's Circle, causing significant vehicular movement issues and traffic jams on major roads.
Train Services Severely Affected
Suburban railway services were hit hard, with rainwater accumulating on tracks. The Central Railway's Trans-Harbour line between Thane and Vashi/Panvel faced a track cave-in due to excessive water flow between Turbhe and Koparkhairane stations. A Central Railway spokesperson stated, "Track cave-in occurred because of excess water flow." The up line was declared unsafe at 5:06 am and restored at 7:27 am with a speed restriction of 10 kmph, while the down line was unsafe from 5:50 am until 7:35 am, when trains were permitted to run at 30 kmph. Commuters reported delays and overcrowding on Central Railway corridors during the morning peak hours. Western Railway services, however, operated normally despite the heavy rain.
High Tide and Alerts Issued by IMD
The Brihanmumbai Municipal Corporation (BMC) reported a high tide of 3.41 metres at 8:28 am, with another of 3.35 metres expected at 7:41 pm. The combination of heavy rain and high tide often leads to waterlogging in the coastal city. The India Meteorological Department (IMD) issued a red alert for Mumbai and Palghar at 4 am on Wednesday, valid for three hours, warning of thunderstorms, lightning, intense to very intense rainfall, and winds of 40-60 kmph. This was downgraded to an orange alert at 7 am for the next three hours, with moderate to intense rainfall forecast for Mumbai, Thane, Raigad, Palghar, and Sindhudurg districts.
Historical Context of Monsoon Onset
The normal onset date of the monsoon in Mumbai is June 10. In 2023, the monsoon arrived even later, on June 25, according to IMD data. The longest delay was recorded in 1974 and 1958, when the onset occurred on June 28. Civic and disaster management teams remain on alert as rainfall activity is expected to continue.
