When Will Monsoon Arrive In Mumbai? Why The Early Onset Of Rains? What’s The Trend Since 2015

Last Updated:May 20, 2025, 19:50 IST

Mumbai Monsoon Forecast 2025: IMD says favourable wind and pressure conditions are likely to advance southwest monsoon, traditionally expected over Mumbai around June 10

The monsoon plays a vital role in Mumbai’s ecosystem and economy. (PTI File)

Monsoon in Mumbai 2025: Mumbai may welcome the monsoon ahead of schedule this year, with the India Meteorological Department (IMD) predicting its arrival in Maharashtra between May 27 and 29. The forecast, shared in early May, suggests favourable wind and pressure conditions are likely to advance the southwest monsoon, traditionally expected over Mumbai around June 10.

According to a report by Navbharat Times, this early onset is linked to the weakening of El Niño, a climate pattern known to disrupt monsoon cycles. With its decline, ocean temperatures and atmospheric conditions are aligning to support a timely and possibly stronger monsoon across the western coast.

MUMBAI’S MONSOON IN PAST 10 YEARS

Monsoon onset in Mumbai has varied widely in recent years. While some years saw an early or near-normal arrival, others — like 2019 and 2023 — experienced significant delays. Notably, in 2019, the monsoon arrived on June 25, marking the most delayed onset in over four decades, as reported by Hindustan Times.

Here’s a look at the past decade:

WHY MONSOON MATTERS FOR MUMBAI

Beyond the waterlogged streets, the monsoon plays a vital role in Mumbai’s ecosystem and economy. The city’s entire water supply, including reservoirs like Tansa and Vihar, depends on timely and sufficient rainfall. A delayed or deficient monsoon often leads to water rationing and supply challenges.

The season also influences agricultural output in surrounding districts, which in turn affects food prices and supply in the city. Additionally, heavy rain tests the city’s infrastructure, regularly disrupting transport and increasing the risk of flooding and disease outbreaks.

Looking ahead, the IMD’s 2025 seasonal outlook has forecast above-normal rainfall, estimating it at 105% of the long-period average (LPA), with a ±5% margin, according to Mint. This is positive news for water reserves and agriculture, although it also means the city must brace for the challenges that come with heavier rain.

WHAT RESIDENTS SHOULD DO

With rain expected to arrive early, the Brihanmumbai Municipal Corporation (BMC) and residents are urged to begin preparations. Clearing drainage lines, strengthening flood response systems, and raising public awareness around monsoon-related illnesses are critical steps in ensuring Mumbai remains resilient through the season.

Staying updated via IMD advisories and credible weather bulletins will be key to navigating the coming months.

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