If you live in a part of the country where it snows, you’ve likely said or heard someone say, "it smells like it is going to snow."
But can you actually smell snow? Well, yes and no.
Air, indeed, has a different smell leading up to a snowstorm. One ingredient for snow is cold air. Cold air is naturally quite dry, and that lack of humidity can stifle your sense of smell. This stifling is the result of mucus around olfactory receptors drying up.
Humidity rises, and atmospheric pressure changes leading up to a snowstorm. The increase in humidity subtly changes the smell of the air while also moistening the mucus around olfactory receptors.
Simultaneously, the cold air and pressure change stimulates the trigeminal nerve in your nose. While the trigeminal nerve is not responsible for smells, it provides certain sensations associated with certain smells. For instance, trigeminal nerve stimulation is why mint smells "cool."
The subtle changes in the air, coupled with the stimulation of the trigeminal nerve, allow the human nervous system to sense a difference in the weather, which may account for the perceived smell of snow.
Once the snow is on the ground, it can take on a host of new smells primarily influenced by its location.
Snow in rural areas typically absorbs molecules from trees, grass, and other plants. These molecules tend to give it a more earthy or woodsy smell.
On their way to the ground, the ice crystals that makeup snow absorb molecules in the air. As a result, urban snow can often smell more oily or dirty.
A study completed in 2021 found that snow purifies the air because it absorbs so many airborne molecules. However, this means that snow on the ground likely contains pollutants from the air, which can affect its scent.
So, the next time your FOX Weather App tells you that snow is in the forecast, step outside and take a whiff of the air. You may be able to smell it coming yourself.