Illinois Air Quality & Wildfire Smoke
Live AQI for 1 Illinois city, plus statewide air-quality alerts. Data from AirNow (U.S. EPA).
Wildfire smoke in Illinois
Smoke risk across Illinois concentrates in the summer months, driven by long-range transport from fires hundreds of miles away.
We currently track one city in Illinois. Its reading is for that monitoring area only and should not be read as a statewide figure.
Each city page below shows AirNow's reported AQI on the 2024 EPA breakpoints, with the reporting monitor and the observation time — see how we calculate AQI. Statewide watches and warnings come from the National Weather Service and appear at the top of this page when active.
The 2,746,388 people we track in Illinois are all in the Chicago area, so this page is effectively that metro's page with a wider lens. For the rest of Illinois, the nearest tracked reading in a bordering state is usually the better proxy than a number from the opposite corner.
Cross-border check: the nearest city we track outside Illinois is Milwaukee, WI, about 81 miles north of Chicago. Smoke does not stop at state lines — when a plume covers that city's monitors, Illinois's edge nearest it is usually seeing the same air.
Our next-nearest tracked readings sit in Madison, WI (123 mi northwest) and Grand Rapids, MI (126 mi northeast) — useful second opinions when Illinois's own reading looks odd, and the honest picture of how coarse national smoke coverage is at this resolution.
About our Chicago coverage
Chicago is one of the Illinois cities we track, with a population of about 2,746,388, in Cook County.
A city this size carries its own year-round PM2.5 baseline from traffic, construction and industry, so wildfire smoke here arrives on top of an existing load rather than against clean background air. That matters for reading the number: a moderate AQI in Chicago on a smoke-free week is normal, and the same AQI during a plume means considerably more smoke than it would somewhere with a lower floor.
Smoke risk here concentrates in the summer months, driven by long-range transport from fires hundreds of miles away. Outside that window an elevated reading in Chicago is more likely to be local — traffic, dust, or a temperature inversion holding everyday pollution near the ground — than wildfire smoke, and the dominant pollutant shown above is what tells the two apart.
For smoke preparation that applies anywhere — filtration, masks, a clean room — see our wildfire-smoke health guide and the clean-room setup.