Number of rain days down by 19% in last four years: BMC

Mumbai has over the last four years seen a gradual decline in the number of rain days, states data compiled by the disaster management department of the Brihanmumbai Municipal Corporation (BMC). While it rained on 106 days during the monsoon season in 2006, it only rained on 92 days in 2008. The number further came down to 86 in 2009.

Interestingly, however, even as the number of rain days decreased by almost 19%, for the last year when rains were deficient, the total rainfall witnessed has not deviated much.

If at all, there was a slight increase in the total rainfall. In 2006, the annual average rainfall was recorded at 2,368 mm, while in 2008, the corresponding rainfall was 2,508 mm. Extreme rain events have increased due to climatic changes and global warming, a senior civic official said.

According to the BMC data, it rains on 29 days in July on an average, while the average rainy days in August during four years was 28. At 18 days, June witnessed least rain days and September was next with an average 21 days.

The BMC data was also corroborated by a paper presented on ‘Mumbai’s urban flooding vulnerability: preparedness and mitigation’ by IIT scientist Kapil Gupta.  In his paper, Gupta said that 50% of the annual rains was received in 2-3 events. As per the BMC’s rain data, the city receives an average 2,294 mm of rains annually.