Chicago wildfire smoke forecast
The map above shows NOAA HRRR-Smoke near-surface PM2.5 for the next 48 hours, updated hourly, with active fires from NIFC and live AQI from EPA AirNow monitors. It opens over Chicago.
Chicago is flat and sits on the western shore of Lake Michigan, and the lake is the only local feature that changes the picture. The lake breeze can hold a shallow layer of cooler air along the shoreline, which sometimes separates lakefront readings from those a few miles inland during the same episode.
Where the smoke comes from
Canadian smoke on northerly and northwesterly flow accounts for nearly all of Chicago's worst air. There is essentially no local wildfire source, so a severe smoke day here means a large fire complex a thousand miles away and a pattern that steers it south.
How long it lasts
A wind shift, and nothing else. These episodes typically arrive and depart with the synoptic pattern over a period of days rather than hours, and the lake breeze modulates where within the metro the worst readings show up rather than whether they occur.
Past smoke events
On June 27, 2023, Canadian smoke pushed Chicago briefly to the worst measured air quality of any major city in the world, with AQI above 200 across the metro. Several shorter episodes occurred through that summer and again in 2026.
Running, riding, and trailheads
The Lakefront Trail is the region's main running and riding route and sits right at the boundary the lake breeze creates, so it can read meaningfully differently from the neighbourhoods just inland. Comparing the two on the map before a long run is the one local trick available here.
Reading the map
Most of this smoke starts in Canada, so switch the map to the ECCC FireWork model, which resolves Canadian sources HRRR-Smoke can underplay. Compare the two with the layer toggle.
Near-surface is the product that maps to what you breathe and to AQI, not the high-altitude column that only tints the sunset. A sky that looks bad and a monitor that reads fine are usually both correct, and they are describing different layers of air.