Monsoon arrives in Mumbai; earliest onset in 75 years, says IMD official

Mumbai: The southwest monsoon made its onset over Mumbai on Monday, more than a fortnight before its normal date, with IMD officials saying it is the earliest arrival of rains in the country’s financial capital in 75 years.

“Southwest Monsoon has advanced to Mumbai today, 26th May 2025, against the normal date of advancement, 11th June. Thus, the monsoon has arrived in Mumbai 16 days earlier than usual. This marks the earliest monsoon advancement over Mumbai during the period 2001–2025,” read an official statement issued by the IMD.

The normal date for monsoon’s arrival in Mumbai is June 11.

In addition to the heavy rain and waterlogging woes, Mumbai’s rainfall has broken a record set in 1918.

As per the Indian Express, records from the Brihanmumbai Municipal Corporation (BMC) show that several parts of South Mumbai received over 200 mm of rain between midnight and 11 am on Monday.

Furthermore, at the Colaba observatory, Mumbai recorded its highest rainfall at 295mm. The previous record was created in May 1918 with rainfall up to 279.4mm.

As per PTI report, IMD data stated that Colaba received 105.2 millimetres of rainfall, Santacruz (55 mm), Bandra (68.5 mm), Juhu Airport (63.5 mm), Chembur (38.5 mm), Vikhroli (37.5 mm), Mahalaxmi (33.5 mm) and Sion (53.5 mm) between 8:30 am to 11 am on Monday.

The rains in May also mark Mumbai’s earliest monsoon in 75  years. As per IMD data, the average date for the onset of the monsoon season in Mumbai stands at June 11. In 2024, the southwest monsoon began on June 6.

“Southwest monsoon made its onset over Mumbai on May 26. This is the earliest onset in the last 75 years,” India Meteorological Department (IMD) scientist Sushma Nair told news agency PTI.

However, with the red alert in the region, the weather department has officially marked the start of the southwest monsoon, 16 days earlier than usual.

On Monday, the IMD upgraded its ‘orange’ alert to red alert for Mumbai, Thane, Raigad, and Ratnagiri districts. Along with a warning in Mumbai, the IMD has also issued alerts for Karnataka, Kerala, and parts of Tamil Nadu.

“Southwest Monsoon has further advanced into some more parts of central Arabian Sea, some more parts of Maharashtra including Mumbai, Karnataka including Bengaluru, , remaining parts of Tamil Nadu, some parts of Telangana and Andhra Pradesh, some more parts of westcentral & North Bay of Bengal, Remaining parts of Mizoram, entire Tripura, Manipur, Nagaland, Arunachal Pradesh, some parts of Assam and Meghalaya, on May 26,” said IMD.