Outdoor exercise
Is it safe to run in Chicago today?
Live AQI and the best running window for Chicago based on Open-Meteo hourly forecasts.
Running today
Caution — shorten or lighten your run
Conditions are borderline. Healthy adults can usually still run outdoors, but consider shortening the session, easing the pace, or moving to the best window identified below. Anyone with asthma, COPD, heart disease, or who is pregnant should be more cautious and may prefer an indoor session today.
Current AQI in Chicago
107
Unhealthy for Sensitive Groups
Updated 31 Aug 2026, 17:00
Best window to run (next 12h)
00:00 – 01:00 · lowest ~51 AQI
Hourly AQI (next 12 hours)
Now
56
18:00
56
19:00
56
20:00
55
21:00
54
22:00
53
23:00
52
00:00
51
01:00
51
02:00
53
03:00
56
04:00
57
What affects air quality for runners in Chicago
Chicago air quality reflects a mix of urban traffic emissions, industrial influence, and changing lake-driven meteorology. Nitrogen dioxide tends to rise near expressways and freight corridors, while particulate levels vary across neighborhoods with different land use and building density. Lake breeze boundaries can shift pollution concentrations within the metro area.