Mumbai’s Rainiest Days Over The Years: A Look Back At Record-Breaking Rainfall That Left City Crippled

Mumbai’s monsoons are prone to grabbing the headlines. Over the past several decades, the city has seen some extraordinary one-day downpours. From paralysing floods to record-breaking showers, rainfall data from Colaba and Santa Cruz reveals how intense the city’s monsoon can get.

Here’s a look at the heaviest single-day rainfalls recorded since 1991, from June to September .

In Colaba, the wettest single day since 1991 was Jun. 10, 1991, when the station recorded over 400 mm of rainfall. The second-highest was 279.4 mm on Jun. 24, 2007, followed by other significant downpours like 248.6 mm on Jun. 28, 1998, 233 mm on Jun. 23, 1999, and 210 mm on Jun. 25, 2010.

In July, Colaba’s heaviest single-day rainfall came on Jul. 28, 2008, with 249.7 mm, followed closely by 243.7 mm on Jul. 4, 2000. Other notable July records include 228.4 mm on Jul. 16, 2014, 227.8 mm on Jul. 1, 2022, and 223.2 mm on Jul. 27, 2023.

August has seen some formidable rainfall too, with the heaviest being 331.8 mm on Aug. 6, 2020. This was followed by 261.9 mm on Aug. 10, 1998, 244.2 mm on Aug. 23, 1997, 191.6 mm on Aug. 7, 2006, and 174.9 mm on Aug. 12, 1992.

In September, Sep. 10, 2005, stands out with 217 mm, the highest since 1991. Other heavy spells include 210 mm on Sep. 20, 2017, 206.9 mm on Sep. 23, 1993, 194 mm on Sep. 4, 2009, and most recently 169.2 mm on Sep. 26, 2024.

In June the highest one-day rainfall was recorded on Jun. 10, 1991, with 399 mm. Other major spells include 283.4 mm on Jun. 19, 2015, 234.8 mm on Jun. 29, 2019, 231.4 mm on Jun. 25, 2018, and 231.3 mm on Jun. 10, 2021.

July produced the city’s most infamous deluge on Jul. 27, 2005, when Santa Cruz logged a record 944.2 mm in 24 hours. The next heaviest July rains were 375.2 mm on Jul. 2, 2019, 351.5 mm on Jul. 17, 2000, 274.1 mm on Jul. 15, 2009, and 267.9 mm on Jul. 8, 2024.

In August, the highest one-day rainfall was 346.2 mm on Aug. 23, 1997, followed by 331.4 mm on Aug. 30, 2017. Other August spells include 268.6 mm on Aug. 4, 2020, 232.6 mm on Aug. 29, 2011, and 224.2 mm on Aug. 7, 2006.

For September, Santa Cruz’s record since 1991 came on Sep. 23, 1993, with 312.4 mm. This was followed by 303.7 mm on Sep. 20, 2017, 286.4 mm on Sep. 23, 2020, 242.2 mm on Sep. 5, 2019, and 223.3 mm on Sep. 10, 2005.

In Colaba, some of the most extreme single-day rainfall events between June and September were recorded over the past five decades. The heaviest was on Jul. 5, 1974, when the station logged 575.6 mm in 24 hours. This was followed by 544.3 mm on Jul. 31, 1984, and 477.6 mm on Jun. 10, 1991. Other significant downpours include 421.2 mm on Jun. 16, 1990, and 417.2 mm on Jul. 30, 1975, all of which underline how ferocious Mumbai’s monsoon can be.

At Santa Cruz, the numbers are even more staggering. The station’s all-time record came on Jul. 27, 2005, with a historic 944.2 mm in just one day. Other extreme events include 399 mm on Jun. 10, 1991, 375.2 mm on Jul. 5, 1974, 351.5 mm on Jul. 17, 2000, and 346.2 mm on Aug. 23, 1997. These figures show why Santa Cruz is often regarded as the epicenter of Mumbai’s heaviest monsoon downpours.