neighborhood-by-neighborhood air – Chicago has started using a citywide network of solar-powered air monitors that can track pollution neighborhood by neighborhood in real time—aimed at a summer when air quality often deteriorates. The system grew out of a civil rights dispute tied to relocatin
On a clear June day. Serap Erdal paused at a light pole in the middle of Grant Park and pulled up her phone. Above her. a solar-powered air quality monitor fixed to the pole kept collecting the air’s signal—small and steady. about the size of a tissue box. Behind her, buses, cars, and cyclists kept moving through the city’s hum.
Erdal zoomed in on a palm-sized map of Chicago, then watched for the numbers to settle. A bright green dot flashed.
“Currently. the air quality index at this location is 31. ” said Erdal. a professor of environment and occupational health sciences at the University of Illinois Chicago. The reading placed Grant Park in the U.S. Environmental Protection Agency’s safest category, meaning it poses little to no risk to public health.
Minutes later, that same network delivered a different story from the far South Side. Even on good days, the monitors have shown, pollution doesn’t land evenly from neighborhood to neighborhood.
That unevenness is exactly what Chicago is now trying to capture—because this is the season when air pollution tends to worsen, in part because climate change is intensifying the conditions that trap emissions closer to the ground.
The monitors Erdal uses are part of Open Air Chicago, a 5-year project that went live last fall. The idea is to collect local air data that shows Chicagoans real-time pollution figures, data the city says can help shape guidance for permitting, urban planning, and air-quality control.
Today. there are 277 air monitors collecting pollution data from every ward and community area. with special emphasis on communities already overburdened by pollution. Each monitor sits less than one mile from the next. and the low-cost equipment measures concentrations of two airborne pollutants: nitrogen dioxide. formed by the combustion of fossil fuels; and PM2.5. particles small enough to pass through a person’s respiratory system and enter the bloodstream—about one-twentieth the width of a single human hair.
Exposure to both pollutants is linked to childhood asthma and cardiovascular issues.
The program’s next phase is arriving with summer—when sunlight and warm temperatures can cook emissions already in the air and form ground-level ozone. Seasonal smog can worsen further as smoke from wildfires becomes more common.
Open Air Chicago can trace its origins back to 2018. when the city sought to relocate a massive scrap-metal shredding operation. General Iron. from mostly white Lincoln Park to the predominantly Latino and Black Southeast Side. In 2021, local environmental activists filed a civil rights complaint with the U.S. Department of Housing and Urban Development, arguing the move discriminated against low-income communities of color and harmed their health.
After negotiations, the city and community groups reached a settlement in 2023. The agreement included the city-wide air monitoring network. Chicago officials partnered with the University of Illinois Chicago to launch the monitors last fall at a cost of over $4 million.
Oscar Sanchez, director of the Southeast Environmental Task Force—one of the groups that successfully filed the civil rights complaint—pointed to what the monitors can do for the communities that asked for proof, not promises.
“This air monitoring system is creating an ongoing record of what the air quality is in Chicago,” Sanchez said. He said the data can be used to corroborate whether new policies are improving air quality or if there are parts of the city with worse air than residents already knew.
Even as air quality has improved over recent decades, the Midwest still experiences periods when conditions turn dangerous. Experts say climate change is exacerbating these swings.
Daniel Horton, an assistant professor of earth and planetary sciences at Northwestern University, said the region is being hit by wildfire conditions that intensify beyond what people can plan for.
“We also have to deal with the consequences of increased frequency and intensity of wildfires,” Horton said. “That’s a problem that doesn’t necessarily occur in our backyards, but when the wind blows in the right direction, we suffer the consequences in the Midwest.”
The stakes are not theoretical. Wildfires have already burned through 2.5 million acres nationwide in 2026—nearly double the 10-year average for this time of year. A recent study published earlier this month in the journal Science said the surge in wildfires. tied in part to climate change. is reversing the country’s steady progress toward improving air quality.
As Midwest air changes with warming temperatures, Horton said the Open Air Chicago network will be able to identify localized pollution hot spots. It can provide an “unprecedented look at the air quality landscape across the city,” he added.
That “unprecedented” view is also about how the data is gathered. The local network can build on top of existing information from the EPA’s handful of regional air monitoring sensors and satellite data from NASA.
Carl Malings. an assistant research scientist at Morgan State University and NASA’s Goddard Space Flight Center. said the local ground readings matter because satellites can capture the complicated interplay of particles and gases across layers of the atmosphere. making it hard to know what people are actually breathing.
A satellite can spot a smoke plume moving over the Midwest, Malings said, but without additional detail it can be unclear whether the smoke is reaching ground level and affecting human health or simply passing overhead.
By combining higher spatial resolution data from satellites with Chicago’s low-cost ground network, Malings said, the city can get a clearer picture of how air pollution concentration levels vary by neighborhood.
At the Chicago Department of Public Health, Grace Adams—the project administrator—checked a sensor readout on her phone.
The network is funded through the beginning of 2030, and city officials hope to keep it online even longer. Erdal said she’s looking ahead to what the next five years can build—data that can help turn summer risk into something measurable. and then into a roadmap for city officials and community leaders to cut down Chicagoans’ exposure to unsafe air.
For now, Chicago is entering its first summer of this neighborhood-by-neighborhood monitoring system. On some blocks, the monitors will keep flashing green. On others, they already have flashed yellow. And this year, the city is prepared to count every color as it happens.
Chicago air quality Open Air Chicago neighborhood monitoring PM2.5 nitrogen dioxide summer smog wildfires civil rights complaint HUD University of Illinois Chicago EPA NASA