Mumbai has been witnessing heavy and continuous rainfall from August 16 to 19, with the city recording extremely high levels of rain in just a few days. The spell, which started on the evening of August 15, is being driven by a combination of weather systems that have strengthened the southwest monsoon.

Why so much rain?

Meteorologists say that two major systems are responsible for the prolonged rain. A low-pressure area over the Bay of Bengal and an east-west trough over the Arabian Sea are together pulling in large amounts of moisture. These systems have locked moisture over the city, creating conditions for continuous rainfall.

Normally, monsoon showers in Mumbai are heavy but intermittent. This time, however, the trough has remained stationary, which means moisture-laden winds are stuck over the region. As a result, clouds have kept forming and dumping rain for several days without a break.

Rainfall and impact

The result has been massive rainfall across the city. Some areas recorded over 200 mm of rain in 24 hours, and in just about 80 hours, Mumbai accumulated 550 mm of rain, nearly equal to an entire month’s average rainfall for August. The heavy downpour forced the closure of schools, colleges, and government offices on Tuesday, bringing the financial capital to a halt.

August rainfall

August is usually Mumbai’s second-wettest month, with an average of 560–620 mm of rain. But this year, the city has already received that amount in just a few days. While heavy spells are common during the monsoon, what makes this one unusual is its multi-day persistence.

In comparison, the 2005 Mumbai floods were marked by a single-day extreme of 944 mm. The current event, however, is stretching across several days, making it disruptive in a different way.

Climate change connection

Experts say such long and intense spells of rain could be linked to climate change and warming oceans, which increase the moisture-holding capacity of the atmosphere. Warmer oceans feed more energy into monsoon systems, making rainfall heavier and more frequent. However, scientists caution that a direct connection can only be proven with long-term data and analysis, not from one isolated event.