Mumbai Monsoon Performance  (2026) till August end:

June: Colaba.441 mm  Scruz 416 mm

July: Colaba 1177 mm. Scuz 1492 mm

August : Colaba.163 mm... Scruz 315 mm 

( Normal for August is 570 mms for Scruz and 460 mms for Colaba.)

Driest August ever: Colaba: 83 mms( 1943): Scruz 109 mms ( 1972)

Seasonal Total 2026 (1st June - 31st Aug) 

Colaba: 1782 mms (+1%)  Scruz: 2223 mms (+14%)

Mumbai and West Coast rainfall is normally activated by Low Pressure Systems from the Bay. 

The striking feature of 2026:

The number of systems from Bay this year (2026):

June: 0 → July:3 → August:4

What really stands out is June 2026 = 0 Bay LPS  (compared with active Bay development in the previous three years. 2025 already had 3 Head Bay systems during June alone.)

Then the situation reversed in July 2026:

Number of systems; June 2026: 0 → July: 3 → August  4

That helps explain the extraordinary contrast between the very weak/delayed Maharashtra monsoon in June and the abrupt switch to very active conditions from early July.

All August systems in August encountered stiff resistance in pushing West inland Hence the west coast off shore trough did not get activated. Explaining the poor rainfall.

With No signs of very effective strong systems coming in the near future, we may see only around 300-350 mms rainfall for Mumbai in September. 

Normal for September is Colaba; 356 mms, Scruz: 384 mms