Southwestern Pennsylvania residents woke to smoke on Friday, as Allegheny County warned residents to avoid outdoor activities and the City of Pittsburgh closed pools and nixed movies and events.

The smoke stems largely from wildfires in Ontario and Minnesota. The Environmental Protection Agency’s AirNow map shows high levels of pollutants in the region.

On Thursday, the county Health Department issued a Code Maroon air quality alert — the most severe level — after concentrations of tiny PM2.5 particles reached hazardous levels.

The department recommended that people stay inside to the extent possible. People particularly sensitive to air quality — potentially including those with asthma, bronchitis, emphysema or other lung diseases — should stay indoors and “keep activity levels low,” the county cautioned. So should children, teens and older adults.

County Executive Sara Innamorato said this means it’s hazardous for everyone, not just sensitive groups, to be outside Friday. But there is hope for relief on Saturday, she said, with rain in the forecast. “Hopefully this heavy smoke will clear the area tomorrow,” she said. “But today we want to encourage everyone to stay safe.”

For people who don’t have air conditioning inside, Innamorato was encouraging residents to seek out places like libraries, malls and movie theaters. She said the department of human services was reaching out to people without homes to find cool places to get indoors. And she encouraged people who have to work outside today to take precautions.

A woman walks on a city sidewalk holding a tissue to her nose and mouth, carrying a floral bag and a white cloth, with blurred people and vehicles in the background.
A woman walks along Grant Street in downtown Pittsburgh, near the City-County Building on July 17. (Photo by Oliver Morrison/Pittsburgh’s Public Source)

Outdoor concerts, other events nixed

Allegheny County canceled its summer concert set for South Park on Friday and closed its pools but hasn’t yet canceled any Saturday events.

The City of Pittsburgh closed pools early on Thursday, and on Friday opted not to open them at all, while cancelling the farmers market on the North Side, plus its Cinema in the Park, Community Pop-Up Concert and Roving Art Cart programs.

The city extended cooling center operations at six Healthy Active Living Centers — in Beechview, Greenfield, Homewood, Mount Washington, Sheraden and the South Side Flats — through 7 p.m. Friday.

Industrial emitters told to curb activities

On Thursday, the county triggered an Air Pollution Episode Warning for the Mon Valley, which compels companies emitting pollution in that area to temporarily reduce activities.

U.S. Steel said in response to questions from Pittsburgh’s Public Source that it “has adjusted operations as required until air quality improves and alerts are lifted” per the county’s episode response plan. The company noted that this week’s air quality problems are driven by wildfires, “not localized industrial activity or inversion conditions.”

U.S. Steel’s Mon Valley Works normally account for around one-quarter of the county’s greenhouse gasses.

Innamorato said that the smoke from wildfires is a reminder for places like Allegheny County to continue to be vigilant about reducing climate emissions. “This is a consequence of inaction,” she said.

Albert Presto, the director of atmospheric particle studies at Carnegie Mellon, said forest fires have led to the worst air quality days in Pittsburgh in the past decade according to measurements in Lawrenceville. “The worst days in that period — and pretty much the only ones to get to orange or worse — were fire days in 2026, 2023 and 2021,” he said.

But this week’s pollution was particularly bad. “I don’t have all of the historical data in front of me,” he said. “but there’s a decent chance that yesterday was the most polluted day that most county residents ever experienced.”

A brick building with a tall smokestack is seen in the foreground, while distant houses and trees are obscured by heavy haze or smog.
The homes and slopes of Troy Hill are barely visible beyond the top floors of the Strip District’s Cork Factory through smoke from Canadian wildfires on July 17. (Photo by Stephanie Strasburg/Pittsburgh’s Public Source)

The Department of Environmental Protection placed the entire state on a Code Red Air Quality Alert status on Thursday. 

The environmental advocacy organization The Breathe Project said it was the fourth such alert in the state’s history, following three such declarations in 2023, when wildfires also polluted the Mid-Atlantic region. 

“Heavy fossil fuel use for more than a century has contributed to global warming and wildfires,” Breathe Project said in its press release. “In Southwestern Pennsylvania, wildfire pollution mixes with and adds to existing pollution from 150 years of industrial pollution. Environmental justice communities face the greatest burden at these times.”

Oliver Morrison is the health and environment reporter at Pittsburgh’s Public Source and can be reached at oliver@publicsource.org.

Help us continue telling stories like this one.

We’re Pittsburgh’s Public Source, an independent, nonprofit newsroom. That means we rely on donations from readers like you to help us report accurate, timely and impactful stories for the Pittsburgh region — available to everyone without paywalls.

Everyone deserves access to credible information to understand and help shape the region they call home, which is why we work hard everyday to deliver fact-checked stories on education, environment, health, local government and more.

We've seen our journalism prompt widespread change in the Pittsburgh region — but none of it would be possible without the support of our community. If you found this story valuable, consider "paying it forward" by making a gift today.

Creative Commons License

Republish our articles for free, online or in print, under a Creative Commons license.

Oliver Morrison is the health and environment reporter at Pittsburgh’s Public Source, covering the systems and conditions that shape people’s well-being, from health care and pollution to infrastructure...