Chicago, IL Air Quality Alert: PM2.5 Levels Reach Unhealthy for Sensitive Groups
On March 4, 2026, air quality in Chicago, IL reached an AQI of 103 for PM2.5, placing it in the Unhealthy for Sensitive Groups category.
Current Air Quality
As of March 4, 2026, the reporting area of Chicago, IL, is experiencing elevated air pollution levels. The primary pollutant of concern is fine particulate matter (PM2.5), which has reached an Air Quality Index (AQI) of 103, categorized as Unhealthy for Sensitive Groups. Additionally, Ozone (O3) levels were measured at an AQI of 21, which is considered Good.
What This Means
An AQI level of 103 indicates that air quality is becoming unhealthy for certain members of the population. While the general public is less likely to be affected at this level, those with specific health conditions may experience adverse effects from breathing the air.
Who Should Take Precautions
Groups at higher risk during this period include:
- People with heart or lung disease (such as asthma)
- Older adults
- Children and teenagers
- People who are active outdoors
What You Should Do
Members of sensitive groups should consider reducing prolonged or heavy outdoor exertion. It is recommended to take more breaks and engage in less intense activities. Watch for symptoms such as coughing or shortness of breath. The general public is not significantly affected at this AQI level and can continue normal outdoor activities.
Source
Data provided by EPA AirNow.
Source: EPA Official Notice