Many people believe they can smell snow coming before it arrives. But is this just an old wives’ tale or is there scientific evidence to back it up? There are a few leading theories that might explain why some people report being able to smell approaching snowfall.
Theory 1: Ozone Levels
One theory suggests that people can smell impending snow due to changes in ozone levels. Ozone is a molecule made up of three oxygen atoms. At ground level, ozone is an air pollutant emitted from cars and industrial facilities. But higher up in the atmosphere, ozone plays an important role in absorbing ultraviolet radiation from the sun.
As a low pressure weather system approaches, bringing with it the conditions for snowfall, it can sometimes force down pockets of high-altitude ozone. This ozone is very reactive and has a sharp, clean smell. If enough ozone gets pushed down to ground level in these pockets, it can become detectable to the human nose. So some scientists think ozone may be the explanation for that “snow smell” some people detect.
Theory 2: Dampness
A second theory points to the increased humidity and dampness in the air before snowfall. When water vapor concentrations rise, this allows odors to become more concentrated and easier to detect. The damp, musty smell before snow may come from wet soil, leaves, pine needles, and other vegetative decay. The odor molecules bind to water molecules making them more prevalent. So the damp air helps intensify smells and makes scents more noticeable to our noses.
Theory 3: Mental Associations
Finally, there is a psychological theory that the “smell of snow” may rely more on memories and mental associations than actual odor changes. According to this view, we notice a certain smell in the air when snow is coming because we have learned to associate it with snowfall based on past experiences.
The smell itself could come from a range of sources – ozone, moisture, vegetation, exhaust fumes, etc. But our brain interprets this particular blend of smells as meaning “snow is approaching” because we have built up that association. So every time we notice that smell profile again, it triggers the snow memory and we believe we are smelling the snow itself.
The Importance of Scent
But whether the smell of oncoming snow is scientifically verified or just a psychological phenomenon, there is no doubt smell plays an important role in weather perception. Scent provides a huge amount of sensory information. The human nose can detect over 1 trillion different odors according to smell scientists.
Here are some other interesting facts about smell and weather:
- Humans can smell rain coming due to chemicals called petrichor released by dirt and plants when rain hits dry ground.
- Ozone levels also tend to rise right before a thunderstorm, producing that characteristic fresh, tingling smell.
- Sharp or foul odors in the air may signal impending tornadoes, electrical storms, or hurricane winds according to some meteorologists.
- Sudden temperature drops can create dense, downward odor flows making scents stand out more clearly.
- Smells travel farther at high altitudes and in cold, dry air, so scent perception changes with the weather.
Clearly, there are strong connections between smells and weather patterns we may not fully understand yet. But smell likely provides valuable subconscious clues about changing weather conditions.
Research on the “Snow Smell”
While the mechanisms are still debated, many people firmly insist they can smell when snow is approaching. Is there any research to back up this popular anecdotal belief? Let’s examine some of the evidence.
A few scientific studies have investigated the human ability to smell impending snowfall:
- A study in the 1970s had over 800 schoolchildren record when they smelled “snow” and when snow later fell. There was a high rate of accuracy, especially among rural children.
- Another study in the 1980s tried to characterize the “snow smell” by collecting air samples before snowstorms. Increased levels of alcohols, aldehydes, ketones, and other compounds were detected.
- Recent research found humans can detect isotopic differences in water molecules by scent. Since snow has a different isotopic ratio, some scientists think this may enable snow detection.
While intriguing, these studies are limited by small sample sizes and inconclusive chemical findings. Clearly more controlled research is needed to investigate the human ability to smell impending snowfall.
In addition to limited studies, there are countless anecdotal reports of people accurately smelling snow coming:
- Interviews with skiers, sailors, farmers, and others working outdoors find many credible accounts of snow smells.
- People often compare the smell to ozone, mint, metals, or chlorine – supporting the ozone theory.
- Descriptions suggest a clean, crisp scent different from other weather smells like rain or humidity.
- Those living in rural areas or at higher elevations seem most attuned to impending snow odors.
So while not scientifically confirmed, many people firmly believe their nose signals snow is near. More research is needed, but these widespread anecdotal reports lend some credence to the phenomenon.
If humans can smell approaching snow, what about our furry friends? Many pet owners swear their dogs, cats, or other animals sense snow coming:
- Dogs may start acting fidgety and odd right before snowfall.
- Cats are seen peering out windows more before a storm.
- Cows and deer gather closer together and orient themselves toward the prevailing winds.
- Squirrels, mice, and beavers become more active stocking up food.
Of course these behaviors could be explained by other cues like changes in barometric pressure, static electricity, or just routine instincts. But it’s intriguing to think smell may play a role in animal snow detection as well.
What would enable a human, dog, or other organism to literally “smell” an approaching snow event? Here are some of the possible explanations science has offered:
As discussed earlier, ozone concentrations rise as descending air masses associated with snow compress pockets of ozone down lower in the atmosphere. Some experts think this increase in ground-level ozone lends a crisp, clean smell that people associate with coming snow.
Snow needs humid conditions to form, so moisture levels spike before a storm. This may allow smelly molecules to bind to water droplets, travel farther, and become more detectable in our noses.
Variations in isotopic ratios between water and snow may create subtle scent differences our nose can pick up on a subconscious level.
Falling barometric pressure has been shown to intensify smells. Low pressure systems linked to snowfall could make odors seem stronger.
Memories and learned associations may wire the brain to interpret certain smells as predictive of snow based on past experience.
Shared instincts or sensitivities to things like ozone, static, or pressure changes may alert animals to coming snow independent of past learning.
Predicting Snow by Scent
Can paying attention to smells actually help predict if snow is coming soon in your area? While not a perfect forecaster, watching for the “snow smell” may provide some clues:
- Be alert for clean, crisp, metallic, minty, or chlorine-like smells on otherwise mild days.
- Take note if familiar scents seem stronger or travel farther than normal.
- Compare your scent observations with weather forecasts to look for correlations.
- Pay attention to animal behaviors – they may pick up on smells imperceptible to us.
- Consider writing down dates and descriptions if you smell something unusual pre-snowfall.
- See if the smell returns repeatedly before winter storms for your specific location.
With practice, noticing the smells in your environment may allow you to make your own snow predictions to complement the weather report!
The Power of Scent Memory
Why might subtle weather scents trigger such strong memories and associations in the human brain? Scent is intimately tied to our memories and emotions in ways other senses are not.
How Smell Memory Works
Science shows scent signals travel a direct route to brain areas handling emotion and memory. Unlike images or sounds, smells get processed through the olfactory bulb which has close links to the amygdala and hippocampus. This gives smells a powerful pathway to memories and feelings.
Studies find scent memories:
- Are more emotional and evocative than other memories
- Are processed faster and more unconsciously than other sensory cues
- Can persist for decades with few repetitions
- Are less impacted by factors like age, trauma, or mental decline
So it makes sense that for many people, a specific smell can serve as a reliable snow memory trigger even over many years.
Snow Scent Memory
Why might the scent memory of approaching snow be so strong? Some reasons snow smells may forge durable odor recollections:
- Snow has a unique scent profile unlike other weather
- It signals a change in seasons and activities
- Snow memories are built up over many childhood experiences
- Snowfalls mark prominent events like snow days or holidays
- Powerful nostalgia and emotion surrounds snow experiences
When you put it all together – the singular smell, the seasonal importance, the youthful experiences – it makes sense why snow has such strong scent associations for many people.
Other Weather Smells
Snow isn’t the only weather phenomenon with a distinctive scent. Here are some other notable weather smells that trigger memories:
The clean, earthy scent of petrichor as raindrops hit dry soil.
A crisp ozone aroma around electrical storms.
Some report a blend of ozone, chemicals, and smoke pre-tornado.
Powerful gales may bring a salty ocean smell inland before landfall.
Stagnant, smoky smells loom ahead of major fog banks.
New growth in spring and decaying leaves in fall carry distinctive scents.
Sudden Temp Changes
Big drops in temperature make smells stand out more.
Just like with weather patterns, the smells people associate with approaching snow likely vary across different climates and geographies. Here are some factors that may influence the “snow smell” in your area:
Higher elevations have different ozone concentrations and air pressure changes that affect scent.
Urban vs Rural
More pollution and obscured scents in cities versus fresh air in the countryside.
Areas near large lakes can have different humidity, clouds, and precipitation patterns.
The origin of incoming air masses brings different scent molecules.
Vegetation like conifers, soil composition, and decaying matter impacts smells.
Wet snow versus dry powdery snow have different scents.
Regions with rare snow build fewer scent memories compared to frequent snows.
So pay attention to the unique scent profile that signals snow in your specific area. Over time, you may be able to reliably smell snow coming!
If you want to become better at detecting scents linked to weather events like approaching snow, try “smell training” your nose. Here are some tips:
- Consciously breathe through your nose and focus on smells during daily routines.
- When an unusual scent hits, make an effort to remember details about it.
- Note scent shifts when the weather changes.
- Track patterns between smells and subsequent weather.
- Test yourself by trying to identify mystery everyday odors while blindfolded.
- Enhance scent memory by associating smells with a visual, name, or emotion.
With diligent practice, you can hone your weather prediction abilities using your nose!
The Science of Snow Scent
While the ability to smell impending snow is not conclusively proven, science suggests some credible possibilities:
|Theory||Logic||Evidence For||Evidence Against|
|Ozone||Falling air pressure with snow compresses ozone down to ground level.||Scientific measurements detect ozone spikes before snow. Many describe a “clean, crisp” snow smell.||Not all snow events have documented ozone rises. The smell varies across different regions.|
|Humidity||Moisture spikes before snow allowing odors to concentrate.||Snow needs humid conditions to form. Damp smells noted pre-snow.||Humidity explains intensity but not the identity of the smell.|
|Isotopes||Nose can detect isotopic differences between water and snow molecules.||Research shows humans can smell isotopic variations.||Isotopic ratios may be too subtle for easy detection.|
Snow Scent in Culture
The idea that people can smell approaching snow shows up in culture and folklore:
- Literature – In Shakespeare’s play The Comedy of Errors, Dromio says “the air is perfumed with snow.”
- Poetry – The poem “Snow” by David Berman includes the line “We can smell the snow.“
- Songs – Kate Bush’s song “Snowed in at Wheeler Street” has the lyric “I can smell snow. I can really smell it now.”
- Folklore – Old sayings claim “When you smell snow in the air, the storm is near.”
This shows snow scent is widely observed enough to be reflected in culture. But more scientific study is still needed.
So can humans truly smell when snow is coming? The jury is still out regarding definitive scientific proof. But the widespread anecdotal evidence, cultural references, and preliminary research suggest there could be some basis to snow having a distinctive scent that people can detect under the right conditions. Much more study is needed on the atmospheric and neurological factors that may enable snow to have an identifiable smell.
In the meantime, next time a winter storm approaches, don’t just look for snow – try smelling for it too! You might be surprised by the power of your own nose to foretell the coming weather.