As colder weather rolls in, Utahns start hearing a familiar term: inversion. An inversion occurs when a layer of warm air traps colder air beneath it, sealing pollutants like particulate matter and vehicle emissions close to the ground. Utah’s geography and climate make these events especially intense, and while they’re most common in winter, the state faces air-quality challenges year-round.
Utah's Four Air Pollution Seasons
Across the year, we don’t just face one air pollution challenge, we face many:
1. Winter Inversion Season – Most severe from December through February, inversions occur when cold air (and all the pollution trapped in it) gets pinned to the ground by a layer of warmer air above. Normally, air is warmer near the ground and colder at higher altitudes; however, our snow-covered valley floors reflect heat during the wintertime months. This creates a situation where the layers of cold and warm air flip, or invert. With emissions from cars, homes, and industry unable to disperse, pollution builds fast and stays longer.
Primary pollutants: Particulate Matter (PM) 2.5
2. Dust Season – Year-round, but especially in drier months, Utah’s arid landscape becomes a source of airborne dust. Without enough precipitation to weigh it down, winds whip up fine particles that reduce visibility and worsen respiratory issues.
Primary pollutant: Particulate Matter (PM) 10
3. Ozone Season – Hot summer days fuel the creation of ground-level ozone, a harmful gas formed when Volatile Organic Compounds (VOCs) and Nitrogen Oxide (NOx) react in the presence of sunlight. Although it’s rare, ozone can also be a wintertime issue. The Uinta Basin is one of only a few places in the country that experiences wintertime ozone issues. Unlike ozone in the upper atmosphere (which protects us), this “bad” ozone can trigger asthma and other lung conditions.
Primary pollutants: VOCs and NOx
4. Wildfire Season – Becoming more intense each year, Utah’s late-summer wildfires send massive amounts of smoke and ash into the air. Even fires burning hundreds of miles away can darken Utah’s skies and pose a threat to public health.
Primary pollutants: PM 2.5 and Ozone
Why “Green” Air Days Don’t Mean We’re in the Clear
Even on days when the Air Quality Index appears safe, there’s no truly “healthy” amount of pollution. Low numbers don’t mean the air is clean, only that it’s less polluted than usual. Over time, even mild exposure affects our health and environment.
Environmental impacts include:
- Hazy skies and reduced visibility
- Soil and water damage from chemical deposition
- Stress on sensitive ecosystems
- Worsening climate change as pollutants trap heat in the atmosphere
Health impacts include:
- Short-term: coughing, wheezing, headaches, throat and eye irritation
- Long-term: asthma, chronic bronchitis, heart disease, stroke risk, and permanent lung damage
Some groups face a higher risk, including children, older adults, people with asthma or heart conditions, and communities located near major roads or industrial zones.
What HEAL Utah Is Doing
HEAL Utah works to build a future where clean air, accessible transit, and healthy communities are the standard, not the exception.
Smart Transit Policy
We support reforms that strengthen public transportation, improve service, and give transit agencies the tools they need to operate effectively and sustainably. We want transit to be a realistic alternative for everyone.
Protecting Communities
We oppose harmful projects like the I-15 expansion and champion alternatives such as freeway caps, land bridges built over highways that reconnect neighborhoods, reduce noise, and improve local air quality.
Community-Powered Data
Through mobility and walk audits, residents identify missing sidewalks, unsafe crossings, and barriers to walking or biking. Their findings help shape safer, more equitable street design, making it safer and easier for pedestrians to get around.
Collaborative Clean Air Solutions
Working with state partners and community coalitions, we’ve:
- Installed mobile air-quality monitors on electric buses to collect neighborhood level air quality data
- Helped secure funding for the Zero Fares for Clean Air program, offering free transit on high-pollution days
Led mobility audits to collect data on improvements needed for safer and more connected street design
Looking Ahead
We are Working to:
- Deepen our mobility audits to gather more community data.
- Push for permanent zero-fare transit days.
- Support the Salt Lake City West-East Connections Study.
- Secure new funding to strengthen Utah’s air quality monitoring network.
- Inform the conversation around how the Olympics can bring new transit and sustainability opportunities for Utah.
While individual actions matter, like carpooling, unplugging unused appliances, and choosing transit when possible, the root causes of pollution often lie in large-scale industries like mining, oil refining, and manufacturing. Still, change begins with us. By advocating for bold policies, engaging our communities, and reimagining how we move through our cities and towns, HEAL Utah is committed to a cleaner, healthier future. Let’s break the cycle of environmental harm and begin to truly heal Utah.
Legislative Recap
Interested in learning more about environmental health during Utah’s 2026 Legislative Session? Check out our blogpost recapping the session today!