Red alert for Mumbai today: 18 days in, Mumbai breaks 1954 September record with 921.3 mm rainfall

“A low pressure is likely to develop over west central Bay of Bengal and adjoining areas of coastal Andhra Pradesh during the next 24 hours. In such a situation, fairly widespread to widespread rainfall with isolated very heavy to heavy rainfall is likely over Maharashtra on September 18 and 19,” read the forecast and warning issued by the IMD.

It further added, “Probable extremely heavy falls over ghat areas of Madhya Maharashtra and North Konkan (including Mumbai) over the next 48 hours.”

Development of low-pressure areas has been keeping the monsoon active and has led to a delay in its withdrawal. The southwest monsoon spans across four months in Mumbai from June to the end of September. This still leaves nearly 12 more days of rain. Last monsoon, the September average rainfall was just 73.1 mm while the lowest September average rainfall was 34.7 mm recorded in 1987.

From June 1 to September 18, Mumbai received 3,475.2 mm rainfall. It is the second highest seasonal rainfall recorded since 1954. The IMD has been recording rainfall for Mumbai since 1954.

The highest seasonal rainfall was recorded in 1958 at 3,759.7 mm while the lowest seasonal rainfall was recorded in 1986 at 1,341.9 mm. In 24 hours, ending at 8.30 am on Wednesday, the IMD’s Santacruz observatory recorded 7.6 mm rain while the Colaba observatory recorded 28.8 mm rain in the same time frame. Neighbouring areas like Panvel recorded 114.6 mm rain, Vasai received 21 mm, Dahanu 38.3 mm, Virar 22 mm, Palghar 34 mm in 24 hours ending at 8:30 am on Wednesday.