Mumbai reels under rain deficit in June, IMD sounds season’s first red alert in MMR

Overall, the Santacruz observatory clocked 416.4 mm rain between June 1 and June 30 while the Colaba coastal observatory logged in 441 mm rain during the month.

Despite continuous showers over the past one week, records show that the city failed to meet its average rainfall quota for the month of June. Making for a deficit of over 25 percent, records from the IMD’s climatological data show that Santacruz observatory receives an average of 526 mm in the month of June while Colaba observatory records 506 mm rain during the month.

The deficit in average rainfall follows the delayed arrival of southwest monsoon in Mumbai this year. While the normal date of monsoon onset for the city is July 11, monsoon advanced into Mumbai on June 23 after a nearly two-week delay. Until the arrival of monsoon, heavy pre-monsoon spells also eluded the city leaving Mumbai and its neighbouring districts parched.

Meanwhile, the rain deficit has left the total stock in the seven lakes catering to Mumbai’s potable water supply dwindling over the month. Despite over 400 mm rainfall recorded in the past week, the total stock in the lakes continued to plummet on Tuesday when the water stock touched 6.75 percent of the total capacity. This marks a stark contrast from last year, when the total stock on the same day had soared upto 40.22 percent or 5.82 lakh million litres.

The dry spell in June comes in line with the IMD forecasting below normal monsoon with only 90 percent of the average rainfall across the country, this year.

However, the Mumbai Metropolitan region is poised for a heavy spell in the first week of July with the weather bureau issuing an orange alert of heavy to very heavy rainfall across Mumbai, Thane and Palghar districts starting July 1. Meanwhile, Raigad district, which encompasses Navi Mumbai, is forecast to experience ‘extremely heavy’ spells on July 2 with the IMD sounding a red alert.

For perspective, orange alert is issued in the likelihood of 115.6 mm to 204.4 mm rain in a span of 24 hours while a red warning is sounded amid possibility of extremely heavy rainfall above 204.4 mm within a day.