Why Does Rain Smell So Good?

You likely enjoy the smell of rain. But you probably don't fully understand why, just like how I don't understand why Superman has to smash so many things while fighting. Avoid buildings! It's not that hard...

But whatever, Superman isn't real. Rain is however, and some scientists think that you have inherited your affection for the scent of rain from your ancestors, who needed rainy weather to survive.

But what makes the rain smell so nice? There are several scents associated with rainfall that people find pleasing.

Petrichor
One is called petrichor. It lingers when rain falls after a prolonged dry spell. (The term was coined in 1964 by two Australian scientists studying the smells of wet weather, which is a specific, weird thing to study) Petrichor is derived from two chemical reactions.

There are certain plants which secrets oils during long dry periods. When it rains, these oils get released into the air. The smell of these oils combines with the smell released by soil-dwelling bacteria known as actinomycetes.
The combination creates Petrichor.

Ozone
The second scent it the scent of ozone. Lightning can split oxygen and nitrogen molecules in the atmosphere, and they in turn can recombine into nitric oxide. This substance interacts with other chemicals in the atmosphere to form ozone, which has a sharp smell faintly reminiscent of chlorine.

If you ever "smell rain coming" it's probably the wind carrying the smell of ozone from an approaching storm.


So there. Science explains it again. Now when you smell rain and are happy, you can thank your ancestors' dire living situation, and chemical reactions.