Is Pittsburgh’s Weather Really Getting Worse?

PHOTO VIA PITTSBURGH MAGAZINE ARCHIVES

If you’ve noticed an uptick in severe weather across the Pittsburgh region, you are far from the only one.

In late April 2025, an “unprecedented” derecho brought “unbelievable” damage to the region, with 90 mph straight-line winds that snapped trees, ripped roofs off of buildings and killed three people in Allegheny and Greene counties.

In January 2026, Pittsburgh received a whopping 15 inches of snow, with some parts of the region reporting more than 20 inches. The accumulation was so severe and so fast-paced that the city’s aging snowplow fleet couldn’t keep up; Mayor Corey O’Connor told the Post-Gazette that only 72 of the city’s 104 snow removal vehicles were roadworthy after the storm. As a result, some secondary roads were left untouched for days, while some were never plowed at all, forcing residents to dig themselves out.

As the nation’s semiquincentennial rolled around in July 2026, extreme heat warnings came to the area, with triple-digit heat indexes and tropical humidity. While no deaths were reported in the Pittsburgh region, multiple heat-related fatalities were recorded across the commonwealth.

Later that same month, wildfire smoke from fires burning in Canada and Minnesota blanketed the region, blurring the skyline in shades of amber, closing down city pools and causing attendees of the annual Picklesburgh festival to don N-95s and respirators as Air Quality Indexes far surpassed the hazardous mark.

In early September 2026, a storm that officials called a “1 in 100 year event” swept through the region, dropping more than 2.5 inches of rain in less than an hour and knocking out powerlines with wind gusts up to 70 mph.

These severe weather events are part of an alarming trend that has been years in the making. Those “unprecedented” storms are becoming very much precedented; tornado warnings, severe flooding and wildfire smoke — all things that were once rarities in Pittsburgh — have become the face of a new normal. 

Experts say the region, and the rest of the world, too, is in a pattern of change, largely driven by human influence in the era of the Anthropocene. 

So what does it all mean?

“A disaster of undreamed proportions”

According to AQI.org, an open-source air quality monitoring platform that keeps track of key climate parameters over time, Pittsburgh ranks in the “high” category for climate change severity, with a 3.2% worsening trend in its overall climate score over the last 16 years. The website says this “suggests deteriorating conditions, with increasing negative impacts on weather patterns and environmental conditions.”

The data points to hotter heat waves and colder cold fronts, as well as more precipitation throughout the year. In other words, summers are hotter, winters are colder and it rains way more than it used to, no matter what season it is.

Experts agree that human activity is to blame.

“The world is warming, primarily or completely from human causes,” says Richard B. Alley, the Evan Pugh University Professor of Geosciences at Penn State University. 

He names the burning of fossil fuels, which release carbon dioxide into the atmosphere, as the primary culprit. 

Fossil fuels are cheap and energy-dense power sources used to generate power for things like electricity, heating, transportation and manufacturing. These resources, especially bituminous coal, are harvested locally and deeply embedded in the regional economy; despite Pittsburgh’s push in recent decades to clean up and green up, Frontier Group names various power plants around the region among America’s top 50 climate polluters, including the Harrison Power Station two hours south in West Virginia and the Cardinal Power Plant an hour west in Rayland, Ohio. 

Closer to home, facilities such as Mon Valley Works — made up of the Clairton Coke Works, Edgar Thomson Steel Works and Irvin Plant — remain one of the heaviest industrial polluters in the region. 

It all contributes to an overall trend of warming, which has played a considerable role in recent weather phenomena, and will continue to play a role as weather patterns continue to shift.

“This is not a new normal — as long as we continue releasing CO2 to the atmosphere, it will continue to intensify these changes. ‘New normal’ to me implies that the changes will cease and we will stay at a new level, rather than continuing to change,” Alley says.

The most apparent changes Pennsylvania residents may already be seeing include “more intense rainfall,” Alley says, adding that the world recently set a new record for the amount of water vapor in the air. 

“When conditions are right, there can be more and more-intense rainfall, and indeed observations are showing an increase in extreme rainfall. Extreme rainfall in turn favors floods,” he says.

Floods, like those that occurred during the “1 in 100 year” storm that struck the region in early September, have rendered sections of major local throughways effectively unusable in their aftermath; Saw Mill Run Boulevard through Brookline, Carrick and Whitehall saw drivers trapped in standing water, and sections of Washington County, including Canton Township, declared a state of emergency following subsequent heavy downpours later that month. 

Granted, Pittsburgh has seen flooding before. There’s the problem of the Bathtub, a flood-prone section of the Parkway East that routinely ends up underwater, which has been slated for infrastructure updates following recent weather events. There’s also the famed St. Patrick’s Day Flood of 1936, largely regarded as one of the region’s worst natural disasters — the epoch of Pittsburgh’s weather consciousness. That year saw a brutal winter followed immediately by a rapid thaw of the rivers’ ice caps; when a heavy spring downpour came, the swollen Allegheny, Monongahela and Ohio rivers washed through the streets of Downtown, cresting to a massive peak of 46 feet at the Point. In the aftermath, 62 were dead, 500 were injured and 135,000 were homeless in what national newspapers called “a disaster of undreamed proportions.” 

PHOTO VIA PITTSBURGH MAGAZINE ARCHIVES | THE FLOOD OF 1936

Detractors often point to historical events such as the 1936 flood as evidence that recent weather phenomena is not caused by any human-made factors, but rather the product of weather patterns that fluctuate with time, like the El Nino/La Nina, a climate pattern that occurs every two to seven years and can dramatically change the weather in certain locations.

However, experts say chalking the weather up to natural variation misses a big part of the story. The assumption is not that extreme weather is happening for the first time, but rather that underlying warming is shifting our baseline, making it harder to predict what the weather will be while simultaneously making severe events more frequent, intense and prolonged.

“Natural variability has always occurred, and always will,” Alley says. “The El Nino/La Nina changes are up and down and up and down and up and down, but you will often get record highs when the up-and-up of human-caused warming combines with the up-part of the natural variability. Then, it is easy to erroneously blame the natural variability for the record rather than the underlying warming.”

An interconnected crisis

Flooding hasn’t been the only weather-related problem the region has seen in recent years, and increased precipitation is not the only indicator of changing weather patterns.

It’s all up in the air — literally. 

Air quality and climate change are “interconnected crises,” experts say, as they share the same root cause: fossil fuels and greenhouse gases.

“Burning of fossil fuels for energy or use in a manufacturing process emits carbon dioxide — the most common and long-lasting greenhouse gas,” explains Patrick Campbell, executive director of GASP, a group formed in Pittsburgh in 1969 to combat the region’s air quality problems. 

While natural greenhouse gases are necessary for life on Earth, the issue is one of moderation; since the Industrial Revolution, Campbell explains that human activity has greatly increased the amount of greenhouse gases in the air, especially carbon dioxide and methane, which trap heat and ultimately make the planet’s average temperature rise. Extra heat means extra energy, which can turn normal weather variations into extreme events.

“If we don’t dramatically cut our greenhouse gases and other air pollution emissions quickly, our planet will continue to heat to dangerous levels,” Campbell warns. “As the planet gets hotter, storms are going to drop far more rain, causing flooding; droughts will intensify, making wildfires — and wildfire smoke — more common and dangerous; [and] heat waves will occur with greater frequency and intensity, killing the most vulnerable of our neighbors.”

It’s a grim prognosis, and one that’s backed by statistics. Allegheny County residents have some of the highest rates in the country of adult and childhood asthma, cancer and premature death due to air pollution, according to data from the American Lung Association’s 2026 “State of the Air” report.

The report, released in April, gave the greater Pittsburgh region straight F’s for air quality, citing an increase in overall unhealthy days from previous years. For ground-level ozone pollution — a powerful respiratory irritant with effects that have been likened to a “sunburn of the lungs” — the region ranks 63rd worst in the nation. For particle pollution, which comes from power plants and wildfires, the region ranked 11th worst. 

Allegheny County also was the area’s worst county, receiving a failing grade for pollution levels well above the federal standard, largely driven by emissions from the Clairton Coke Works in Clairton, the ATI Flat Rolled Products (formerly Allegheny Ludlum) facility in Brackenridge and Thermal Transfer Corp. in Duquesne.

“Clearly, there is much more work to be done to improve air quality, because no one should face a greater risk of asthma, cancer and premature death simply because they live in Allegheny County,” Campbell says.

The immediate impact of that failing grade can also be seen in the region’s shifting weather patterns, further highlighting the relationship between air quality and climate change.

Due to its topography, the Pittsburgh region frequently experiences temperature inversions, during which a warm layer of air forms above a cooler layer of air along the ground. The warm layer of air keeps pollution closer to the ground, where people are more likely to breathe it in. While it’s important to note that temperature inversions are naturally occurring and do not cause pollution themselves, studies have shown that these inversions have increased by up to 50% due to changing climate patterns, meaning that pollution ends up trapped more frequently and for longer periods of time.

As the surrounding Monongahela River valley traps pollution from the Clairton Coke Works during these temperature inversions, nearby residents are routinely breathing some of the worst air in the U.S.

While many of our poor air quality days in Pittsburgh can be traced back to local plants like Clairton’s, another effect of climate change is drawing air pollution in from farther afield.

Campbell, like many lifelong Pittsburghers, can only recall a handful of times in past decades that wildfire smoke reared its head in the region. However, recent years have seen the smelly, heavy air moving in from the west, blotting out the sun and even turning the sky an apocalyptic shade of orange or red for days at a time — a change that experts also say can be attributed to human influence.

“There have been sometimes in the past — I think a time or two in the 1990s — where wildfire smoke minimally impacted our air quality, but nothing like we’ve experienced in the last few years,” he says. “Human-caused climate change is driving this change. Wildfires all over the world are increasing in frequency and intensity as the planet gets hotter, because a hotter world means more intense and frequent droughts.”

PHOTO BY OLLIE GRATZINGER | WILDFIRE SMOKE CAUSED A SMELLY HAZE OVER THE CITY ON JULY 18, 2026.

It’s a sentiment seconded by Penn State’s Alley.

“Any hair dryer or clothes dryer has a heating element because it dries faster. Faster drying can happen in a warming world, too, favoring expansion of droughts,” he says. “Wildfires are complex — they need fuel, a source of ignition (human or natural) and favorable conditions. The scientific literature shows an increase in the favorable conditions for wildfire in many cases.”

A heritage steeped in smog

Pittsburgh’s relationship with its air is complicated. How an industrial town that was once famously referred to as “hell with the lid taken off” could clean up as much as it has is nothing short of incredible, but its recent progress is mixed. While the city’s air is the cleanest it’s been in modern history, it is still often listed among the dirtiest in the county.

This is in part because the facilities driving pollution remain part of a proud heritage of creation, at once integral to the region’s cultural identity and a direct threat to its future. Nostalgia for the old days of industrial manufacturing and Pittsburgh’s golden years are often at odds with the bitter truths about the era, including the long-term impact of the region’s reliance on coal and iron ore.

“Our industrial heritage and our current industrial experiences absolutely impact the air quality in the region. For example, Allegheny County alone has twenty-nine major sources of air pollution,” says Campbell. 

In order for a source to be considered “major,” it must release 100 tons per year of any air pollutant. Data shows that the Clairton Plant alone releases over a million pounds of pollutants annually — closer to 550 tons.

“I think our industrial heritage and present motivates residents to speak out about the harms of air pollution, advocating for better regulations and working to advance sustainable solutions. But, our region must overcome its nostalgia about industries like the steel industry,” Campbell says. “From labor rights and worker safety to public health and environmental health, I would argue the steel industry — particularly the management of U.S. Steel — has done far more harm than good. We need to move beyond fossil fuel extracting and burning processes of the past.”

Particle politics

The question of what the region’s future can look like without fossil fuels remains a hot-button issue in both local and national politics. 

“Clean air is not something we can take for granted. It takes work,” says Harold Wimmer, president and CEO of the American Lung Association. “For decades, people in the U.S. have breathed cleaner air thanks to the Clean Air Act. Unfortunately, that progress is now at risk due to extreme heat and wildfires, fueled by climate change, and policy changes that are making the problem worse.”

Wimmer says that in the last year alone, the Environmental Protection Agency has “weakened enforcement and rolled back rules” that would have protected children from power plant and vehicle pollution. In February, the EPA rescinded the 2009 Greenhouse Gas Endangerment Finding, a formal determination that six key greenhouse gases threaten public health and welfare, which laid the legal foundation for federal climate regulations in the United States. Without it, there is no longer a legal requirement for the federal government to regulate greenhouse gas emissions from motor vehicles or certain power plants.

“Clean air is essential to the health and wellbeing of families across Pennsylvania. Children deserve to breathe air that won’t make them sick,” says Elizabeth Hensil, director of advocacy for the American Lung Association. “Unfortunately, too many people in the Pittsburgh metro area are living with unhealthy levels of ozone and particle pollution.”

Hensil adds that the U.S. The Environmental Protection Agency’s push for deregulation and rollbacks of critical healthy air rules — touted by the Trump administration as “the Great American Comeback” — are having a detrimental effect on local residents, more and more of whom are suffering from asthma and other respiratory diseases.

The solution?

As with any problem, the first step to solving it is to realize it’s actually a problem — and a big one at that.

In April, the New York Times reported that climate change denial has seen an uptick, especially as legislative moves out of Washington, D.C. are “dismantling many of the key actions that have been undertaken at the federal level to address climate change,” according to Columbia University. Data from Yale in 2025 also show that 15% of Americans don’t believe global warming is happening at all, up from just 7% in 2020.

“Human-caused climate change is not a hoax or some cruel thought experiment — it is reality and it is unfolding around us,” Campbell says. “We, as individuals, a country and a global community must act now to mitigate the worst effects of climate change.” 

Experts agree that the primary way to halt climate change is to stop fossil fuel extraction and burning for electricity generation, and to switch to more sustainable methods such as wind, solar and water. 

“We have all of the technology to do this today,” Campbell says. “What we need is political will and investment to do it at scale.”

The electrification of vehicle fleets such as buses and municipal vehicles could also help to lessen the damaging emissions put out by diesel- and gasoline-powered engines, Campbell says. This is something that industry leaders in Pittsburgh say is already in the works; Pittsburgh Regional Transit says it hopes to have a 100% pollution-free fleet by 2045. After 2032, the transit company will only purchase zero-emission battery-electric buses for its 730-vehicle fleet.

PHOTO COURTESY OF PITTSBURGH REGIONAL TRANSIT

 There are only eight fully battery-electric buses in circulation now, along with a few hybrid diesel-electric models, although the majority of PRT’s current fleet relies on ultra-low sulfur diesel and bio-diesel blends, which still release carbon dioxide when burned.

Additionally, a number of the city’s municipal vehicles are electric, and officials say the goal is to transition toward a fully fossil fuel-free fleet by 2030. There are also various initiatives, including the Switch Together program, that can help individuals transition to cleaner energy for their homes at a subsidized price.

The greater challenge, though, may be in shifting Pittsburgh’s identity as a steel town toward a greener horizon.

The Clairton Coke Works is the largest coke-making facility in the Western Hemisphere; its total economic impact is in the billions, and it generates more than $100 million in state and local tax revenue. If the plant were to cease operations today, the air quality across the region would greatly improve, but the national steelmaking chain would all but collapse, and the Mon Valley’s economy would take a serious blow. 

Nevertheless, climate experts agree that change is necessary. While it may be difficult to get everyone on board, experts say a first step could be divesting in manufacturing plants that pollute while simultaneously investing in those that use sustainable energy sources, like electric arc furnaces. These melt and refine recycled scrap metal using electricity, while traditional blast furnaces melt raw materials through continuous combustion, which produces carbon dioxide. 

The use of electric arc furnaces can be supplemented by the use of cleaner hydrogen instead of fossil fuels to power mills — something that is already being done at companies like Ovako in Sweden, Greensteel in Australia and ArcelorMittal in Spain.

“If companies can’t do that, they shouldn’t be in business,” Campbell says.