How Montana Schools Are Using PurpleAir Sensors to Protect Communities from Wildfire Smoke

by Amanda Hawkins
Photo by Steven Cordes on Unsplash

Montana is known for big blue skies, but summers in the state increasingly come with stretches of wildfire smoke that can linger for days or weeks. Across Montana, a statewide initiative called PurpleAirs in Schools is turning local schools into air quality monitoring hubs, and the results are benefiting entire communities, from rural eastern Montana to the mountain valleys of the west.

The Problem: Wildfire Smoke Varies Block by Block

Wildfire smoke contains fine particulate matter known as PM2.5, particles small enough to penetrate deep into the lungs and enter the bloodstream. Short-term exposure can cause coughing, eye irritation, and difficulty breathing. Prolonged or repeated exposure over multiple fire seasons is linked to heart disease, worsening asthma, reduced lung development in children, and increased hospital visits.

Montana's Department of Environmental Quality operates high-quality regulatory-grade sensors in larger cities like Billings, Lewistown, and Havre. But smoke levels vary widely across the state, and for residents in rural areas, their judgment has often come down to whether they can see the mountains in the distance. Terrain, wind patterns, and shifting fire behavior can cause PM2.5 concentrations to differ dramatically over short distances, sometimes within a single town.

As Pam Hanna, Jefferson County's Public Health Supervisor, wrote in The Monitor, "one of the greatest barriers to preventing poor health outcomes from wildfire smoke exposure is the lack of precise, localized air quality information."

PurpleAirs in Schools: A Statewide Program

The PurpleAirs in Schools program, now in its third year, is a partnership between Montana DEQ, the Montana High School Association (MHSA), and the University of Montana. Funded by a $425,000 federal grant through the American Rescue Plan Act, the program provides PurpleAir sensors to schools at no cost.

About two-thirds of Montana's school communities have signed up so far. Each participating school receives two sensors: one for outdoors and one for indoors. The outdoor sensors feed data to the EPA's fire and smoke map, while the indoor sensors help schools understand how outdoor smoke infiltrates their buildings.

"We originally targeted high schools because they're community hubs, but not every place has a high school, so some of those are middle schools," said Kari Nauman, who helps run the DEQ program, in an interview with the Daily Montanan. "We're not actively saying it's for any school, but if a community reaches out and they don't have a sensor, we're gonna provide it."

In Jefferson County specifically, Jefferson High School and Whitehall School already have active PurpleAir monitors, and Clancy School is working to become the third site in the county.

Protecting Student Athletes

High school athletics are a cultural backbone of Montana, with football, cross country, soccer, volleyball, and golf all played outdoors in the fall, right when wildfire smoke is at its worst. Games, matches, and meets are routinely canceled each year, and athletic directors face difficult decisions when conditions are uncertain.

PurpleAir sensors give those directors real data instead of guesswork. Richey-Lambert High School co-activities director Kara Triplett described a particularly tough call from a few years ago, before the school had a sensor, when spring smoke threatened divisional track. "It was such a hard call to make, because you can't push divisional track too far beyond the date that we had set, because we're moving into high school graduations," Triplett said.

Now, with sensors providing live readings, schools across the state can make informed, timely decisions about when to cancel, postpone, or move events indoors.

"We don't want students out there jeopardizing their health for practices and games if we can help it," said Greta Buehler, an associate director with the MHSA.

Beyond Athletics: Indoor Air and Classroom Science

The University of Montana's involvement, led by Professor Curtis Noonan of the School of Public & Community Health Sciences, adds a research dimension to the program. The university helped develop the correction algorithm that makes the sensor data interpretable, and the indoor sensors provide a window into how outdoor smoke infiltrates school buildings.

"It's really helpful for the schools to just know what the outdoor environment's like, and then better understand how that outdoor air impacts the indoor air quality," Noonan said.

The data has also found its way into the classroom. Through the university's Students Participating in Air Research and Knowledge Translation program, students across the state can access and study real-time air quality data from schools statewide.

In one notable example, students at Arlee High School, one of the first schools to receive a PurpleAir sensor, used indoor air quality readings to identify harmful particulates from the school's coal-burning furnace. The students petitioned the school board, and in 2018, Arlee upgraded to an all-electric heating system.

A Model for Other States

The program has drawn national attention. The American Lung Association highlighted Montana as one of six case studies in its "Something in the Air" report, and DEQ has fielded inquiries from agencies in Colorado, Idaho, Arizona, California, and South Dakota looking to implement similar programs.

"Montana's model demonstrates how collaboration can transform low-cost sensor networks from short-term pilot projects into durable public-health infrastructure, capable of adapting to increasing wildfire impacts while continuing to serve under-resourced communities over the long term," the American Lung Association report notes.

A Stanford University study released in fall 2025 found that the health impacts of wildfire smoke are greater than previously understood, with disproportionately higher effects in the western United States. As fire seasons grow longer and more intense, the need for this kind of localized monitoring grows with them.

What You Can Do

  • Check the air in your area. Use the PurpleAir map to see real-time PM2.5 readings near you.
  • Host a sensor. Adding an air quality monitor to your home, school, or community building contributes data to the global network and gives your neighborhood a resource it can point to.
  • Prepare for smoke. Have N95 or P100 respirators on hand, know how to create a clean air room in your home, and avoid activities that worsen indoor air quality (burning candles, vacuuming without a HEPA filter) during smoky periods.
  • Talk to your school. If your local school doesn't have a sensor yet, point them to Montana's model. It's a low-cost, high-impact way to bring air quality awareness to an entire community.

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