A combination of Western wildfires and summer heat is contributing to health concerns surrounding heat and air quality.
The extreme heat is accelerating chemical reactions that produce harmful ozone, a problem for many major metro areas. Combine the particulate matter from wildfires, known as PM2.5 and PM10, and it's a harmful combination for people's health, according to the U.S. Environmental Protection Agency.
Jodi Bechtel with the Clark County Department of Environment and Sustainability, which includes Las Vegas, says stagnant air can contribute to problems.
"The more stagnant it is, the more the pollutants just build up because there's no way for that pollutant to disperse into the atmosphere and no wind to blow it out," she said.
According to AirNow, the federal government's air quality tracker, large swathes of Mountain West states have been blanketed by "moderate" risk wildfire smoke, with a few regions considered unhealthy for sensitive groups, such as those with chronic heart or lung conditions.
In Nevada, officials issued a season-long advisory for ground-level ozone pollution and wildfire smoke, telling people to stay informed about air quality conditions to protect themselves.
As of Monday, air quality is moderate in northeast Arizona and portions of Nevada, as well as northern New Mexico and large portions of Colorado and Utah. Air quality is also considered in the moderate range in some portions of Idaho and Wyoming.
According to the Clark County Department of Environment and Sustainability:
Ozone – is a major component of smog. It is formed when pollutants from vehicles, power plants, and industry (Nitrogen oxides (NOx) and volatile organic compounds (VOCs) – known as ozone precursors) react in the presence of sunlight and heat. This is why it is a summertime pollutant.
Particulate matter – Is a mixture of microscopic solid particles and liquid droplets suspended in air (dust, dirt, soot, smoke). PM 10 is 10 micrometers or smaller. PM 2.5 are 2.5 micrometers or smaller – highly respirable.
Wildfire smoke contributes PM 10 and PM 2.5 to the air and can contribute to nitrogen oxides and volatile organic compounds, depending on the fire fuel.
Heat and air quality. In addition to sunlight exacerbating ozone, high pressure systems across the west can cause a dome that causes warm air to become trapped. The high-pressure forces rising warm air back toward the ground, which compresses as it sinks and releases more heat. Heat causes ground to lose moisture, creating further warming, exacerbating drought conditions and increasing the likelihood of wildfires. The high-pressure dome also prevents clouds from entering, which would help to cool temperatures.
Because the air is stagnant, pollutants can build up to unhealthy levels.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Northern Colorado, KANW in New Mexico, Colorado Public Radio, KJZZ in Arizona and NPR, with additional support from affiliate newsrooms across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting and Eric and Wendy Schmidt.
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