CDPH, UIC School of Public Health Launch Open Air Chicago

CHICAGO - Last week, the Chicago Department of Public Health (CDPH) and the University of Illinois Chicago (UIC) School of Public Health publicly released data from Open Air Chicago, the largest community air monitoring network in the country and second largest in the world.

Over six weeks in summer 2025, a total of 277 Clarity Node-S sensors that measure levels of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) were installed using a scientific, grid-based approach across the City with input from community members participating on the Advisory Board. This network supplements the local air quality data currently available on AirNow.gov, which includes data from federal-grade monitoring systems, to provide air pollutant estimates at the hyperlocal level. The network name, Open Air Chicago, comes out of multiple discussions with the Advisory Board and underscores the openness and transparency of the process, project, and data. By sharing clear, accessible air quality data, the project helps Chicagoans understand the air they breathe and make informed choices to protect their health and communities.

"The power of public health is now in the hands of the public," said CDPH Commissioner Olusimbo "Simbo" Ige, MD, MS, MPH. "CDPH committed to sharing findings from these sensors in early 2026 to ensure residents are empowered to make their own health decisions based on science. We know that certain populations are more vulnerable, and we want all Chicagoans to know what they can do to help themselves and help each other."

Access to Open Air Chicago data is available through the Clarity Open Map, as well as the Chicago Open Data Portal. On the Clarity Open Map, Chicagoans can:

• Identify the air sensor(s) near them,
• Assess current air quality levels and 24-hour trends,
• Review health recommendations related to the current air quality,
• Download measurements from the last 30 days for a specific sensor, and
• Sign up to receive alerts from a specific sensor when air quality becomes "unhealthy."

Those interested in reviewing raw and weighted data can download data for individual measurements, hour aggregations, or day aggregations on the Open Data Portal.

"Open Air Chicago combines cutting-edge air monitoring, academic expertise and democratized public health data," said Wayne H. Giles, MD, MS, dean of the UIC School of Public Health. "Access to accurate, transparent and easy-to-understand information is the first step towards data-driven health policies and more equitable environmental protections."

Open Air Chicago was made possible through support from the City of Chicago, U.S. Senator Tammy Duckworth, the National Institute of Standards and Technology, and ComEd.

To learn more about Open Air Chicago and to access air quality resources, visit the CDPH website.

CDPH Public Information Office: [email protected]

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