Why is there a certain scent when it rains?

Ever notice a scent when it rains? There's a reason for that.


ROANOKE, Va. – Rain, by itself, does not have a scent. However, many of you may notice that there can sometimes be a scent in the air before rain comes. 

It's as if the rain is letting you know, "Hey! I'll be right there."

It has to do with something called petrichor. This is formed when organic matter is decomposed by different types of bacteria in the ground. A byproduct, or aftereffect, of petrichor is a kind of alcohol called geosmin.


Alcohol, naturally, has a strong smell to it. With both petrichor and geosmin naturally in the ground, the rain can sometimes wake these two compounds up and carry them away.


The heavier the rain, the farther that scent can travel downwind. Moisture also allows scent to travel more than just dry air.


Get your sniffers ready! Rain is part of the forecast almost every day for the next week, with some of the most widespread rain coming Friday

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