Is It Possible to Smell If It’s Going To Rain?


Have you ever walked outside and felt like you could smell the rain before it arrived?

Some people swear by this ability, while others think it’s nonsense.

However, there is scientific evidence to support the idea that you can actually smell approaching rain.

The Scent of Rain: Petrichor

One of the main reasons you might be able to smell rain before it starts is because of a scent called petrichor.

The term comes from Greek words: “petros” meaning stone and “ichor,” which is the fluid in the veins of the gods.

Petrichor is that earthy, pleasant smell you notice after it rains, especially following a dry spell.

This smell is produced by a soil bacterium called Streptomyces.

This bacterium releases a compound known as geosmin, which humans are incredibly sensitive to.

Our noses can detect geosmin better than sharks can smell blood in water!

The bacteria produce geosmin to attract insects and other small creatures, which then help spread the bacteria’s spores.

When it rains, water droplets hit the ground and trap tiny pockets of air.

These pockets burst, creating aerosols that carry the scent of geosmin into the air.

These scent particles can travel long distances, allowing you to smell the rain before it actually arrives.

In fact, this process was demonstrated by researchers in 2015, showing how raindrops can create aerosols containing geosmin and other compounds from the ground.

Ozone: Another Rain Indicator

Another factor that contributes to the smell of approaching rain is ozone.

Ozone has a sweeter smell compared to the earthy scent of petrichor.

It consists of three oxygen atoms and can be created by lightning or even human-made pollutants.

Ozone is naturally occurring and is produced when electrical charges, such as lightning or artificial sources, split nitrogen and oxygen molecules in the atmosphere.

Some of these molecules recombine to form nitric oxide, which can then react with other chemicals to produce ozone.

When a thunderstorm is brewing, the storm’s downdraft can bring ozone from higher in the atmosphere down to ground level, where we can smell it.

This can be a sign that heavy rain is on its way.

The scent of ozone in the air often precedes a storm, as downdrafts from thunderstorms bring this distinctive smell to our noses.

The Human Nose: A Powerful Detector

The human nose is remarkably sensitive to these scents.

Geosmin, for instance, can be detected by humans at incredibly low concentrations.

This sensitivity to trace amounts of geosmin helps explain why the smell of rain can be detected well before the rain actually arrives.

Additionally, our noses can differentiate between the slightly earthy scent of petrichor and the sweeter, sharper smell of ozone.

This ability to distinguish different scents allows us to sense changes in the weather more accurately.


So, next time you think you can smell rain in the air, you might be right!

Whether it’s the earthy scent of petrichor or the sweet smell of ozone, your nose is picking up on clues that rain is coming.

These scents, carried by aerosols and downdrafts, travel ahead of the rain, giving you a heads-up.

So, trust your senses and consider grabbing an umbrella just in case.