Temperature Inversions
In Utah

What’s An Inversion?

This is an update to an earlier article about a phenomenon that remains as relevant as ever … temperature inversions in the Salt Lake Valley and along the Wasatch Front. 

If you’re planning to visit Utah in the winter, it’s essential to understand what inversions are, how they form and what you can do to minimize their impact on your trip.

Temperature inversions occur when a layer of warm air traps colder air near the ground.  This creates a stable layer of air that acts like a cap.  Normally, the atmosphere cools with increasing altitude which allows air to rise and mix.

During an inversion, however, the temperature actually increases with altitude (a rare but significant reversal) which prevents normal air circulation.  This stagnant layer traps pollutants, moisture and cold air leaving the valley beneath it enveloped in ugly haze or … let’s be frank … smog.

Why Are Inversions So Bad?

If you visit Salt Lake City during the winter and we’re experiencing one, be aware that inversions can have noticeable and unpleasant effects over and above the obvious negatives:

• Poor Air Quality: Pollutants, including emissions from vehicles and industrial sources, become trapped causing dense haze or smog that can obscure visibility.  At its worst, you may not even see the other side of the valley.
• Health Impacts: Inversions worsen air quality leading to respiratory issues especially for those with asthma, allergies or other conditions.  Prolonged exposure can irritate lungs and reduce overall wellness.
• Colder Temperatures: The trapped cold air leads to much colder conditions in the valley compared to higher altitudes.  It’s a damp, bone-chilling cold that never seems to let up.
• Lack of Sunlight: Inversions block out sunlight leaving the valley in a perpetual gray haze that can feel bleak and depressing.
• Fog and Reduced Visibility: Fog is common during inversions making driving conditions more hazardous.  This becomes even more dangerous due to very limited visibility the closer you get to the Great Salt Lake and Utah Lake in Utah County.
• Reduced Snowfall: Without upward air movement, clouds can’t rise high enough to produce precipitation.  The result?  The snow that we need to break up the inversion is less likely in the valley.
• Mood Effects: The combination of cold, gray skies and poor air quality can lead to frustration, seasonal blues and even depression.

What Causes Inversions in Salt Lake City?

The geography of the Salt Lake Valley plays a critical role in creating temperature inversions.  Surrounded by mountains on all sides, the valley acts as a natural basin where cold air settles.  Long winter nights, snow cover and high-pressure systems create the perfect conditions for inversions:

1. High-Pressure Systems: These bring clear skies, light winds and stable atmospheric conditions that combine to trap cold air.
2. Topography: The surrounding Wasatch and Oquirrh mountains prevent air from escaping the valley.
3. Snow Cover: Snow reflects sunlight and cools the air even further intensifying the inversion.
4. Urban and Industrial Emissions: Vehicle exhaust, industrial activity and other human-made pollutants dramatically worsen air quality during inversions.

Can Anything Good Come from an Inversion?

While inversions are mostly unpleasant, they do offer one very small silver lining: stunning sunsets.  When the sun sets west of the Salt Lake Valley over the Oquirrh Mountains, its rays pass through the trapped haze sometimes producing spectacular reds, oranges, and purples in the sky.  For a brief moment, you might forget about the inversion. 

Another solution to this phenomenon is that you can escape inversions by heading up the canyons.  Just 30 minutes away, ski resorts like Alta, Snowbird, Brighton and Solitude sit above the inversion layer.  They offer crystal-clear blue skies along with warmer temperatures and Utah’s famous snow.

It’s a perfect excuse to hit the slopes while enjoying a break from the valley haze.  If you’re like me and don’t ski due to some painful injuries over the years ... or just don't ski ... simply being up in the mountains can lift your spirits.

How Do Inversions End?

The same weather systems that make Utah a world-class winter destination are also responsible for clearing inversions:

• Winter Storms: Snowstorms, often preceded by strong winds, break up the stagnant layer of air and mix the atmosphere restoring fresh air to the valley.
• Winds: Strong winds help disperse trapped pollutants and push cold air out of the valley.

Utahns often find themselves dreaming about, hoping for and praying for snow during prolonged inversions.  One of the most memorable examples occurred just before the 2002 Winter Olympic Games in Salt Lake City.

Leading up to the Games, a particularly harsh inversion blanketed the city.  It raised concerns about international visitors experiencing the embarrassing smog, haze and ugliness.

Just in time … almost miraculously … a winter storm swept through literally a day or two before the Opening Ceremonies clearing the skies and showcasing Utah’s pristine beauty for the world.

How Can You Minimize The Ill Effects of Inversions?

If you’re visiting Salt Lake City during winter, here are a few tips to minimize the effects of inversions:

1. Head to Higher Elevations: Drive up one of the nearby canyons to escape the inversion. The ski resorts offer clean air, sunshine and incredible winter activities.
2. Stay Indoors During High Pollution Days: Check the Utah Department of Environmental Quality’s air quality index (AQI) to stay informed.
3. Drive Less: Vehicle emissions do contribute very significantly to the problem. If possible, carpool, use public transit or explore by foot.
4. Be Mindful of Health: If you have respiratory conditions, limit outdoor activity during inversions and use air purifiers indoors.

A Longstanding Issue

Inversions have always been part of life in Salt Lake City even before modern vehicles and industrial pollution.  In the early days, coal and wood-burning stoves were the main culprits.  Today, vehicle emissions, exploding population and urban sprawl exacerbate the problem.

While the state continues to work on solutions such as stricter emissions standards and promoting public transportation, inversions are an unavoidable reality of winter in the Salt Lake Valley.

Final Thoughts

My wife asked me why I write about something as gloomy as inversions but I believe visitors should know what to expect when traveling to Salt Lake City in winter.

The good news is that escaping an inversion is as simple as driving up the canyons.  Within minutes, you can leave the gray smog behind and experience blue skies, sunshine and some of the best skiing, scenery and winter recreation in the world.

So, don’t let inversions keep you from enjoying Utah’s beauty.  Plan ahead and stay informed by checking long-term weather forecasts.  They are often able to tell far in advance when we will be experiencing one of the things we put up with to live here. 

You can time your visits to avoid the bad air if you are able to.  Then you’ll be able to embrace the unique experiences that winter in Utah can offer. 

Frequent snowstorms and the movement of these storms through the state are the main factors in producing "the best snow on earth" while at the same time avoiding these nasty inversions.  That's why we’re always hoping for the next winter storm in Utah.   

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