Will I be hot?
Will I be hot in Mumbai in September?
Verdict
Yes — Yes, hot.
Highs push 87°F — sun exposure and hydration matter more than layering.
Day vs. night
Day
87°F
Hot
Prioritize shade, hydration, and a brim.
Night
76°F
Warm
Still warm enough for a T-shirt after dark.
Why
Mumbai in September averages highs of 87°F, lows of 76°F, 16 rainy days.
Prioritize breathable fabrics, sun protection, and hydration over any kind of layering piece.