When it "smells like rain" before it starts to rain, what makes that smell? No other form of water has it>

Question

When it "smells like rain" before it starts to rain, what makes that smell? No other form of water has it>

Answer 1

I have no idea what it smells like before it rains but I can

tell you that you can 'smell snow'.  I think it means that you

can detect when breathing in the change in the temperature

and experience has taught you that change means that snow is coming. Maybe it is the same for rain.

Answer 2

Pollution, specifically ozone.

I noticed the smell the first time it rained in Los Angeles when my family moved there when I was about 6.

The smell was so bad I started coughing.

Answer 3

It's a types of plants that give off a scent when it is about to rain.