Air Quality Alert: Denver-Boulder Air Quality Reaches Unhealthy for Sensitive Groups Level

Current Air Quality

In the Denver-Boulder, CO reporting area, the air quality index (AQI) reached a peak of 104 on February 23, 2026. The primary pollutant of concern is PM10, which is currently in the “Unhealthy for Sensitive Groups” category. Other measured pollutants include PM2.5 at an AQI of 78 (Moderate) and Ozone (O3) at an AQI of 45 (Good).

What This Means

An AQI of 104 falls into the “Unhealthy for Sensitive Groups” category. According to standard EPA guidance, this level indicates that air quality is unhealthy for certain groups of people, while the general public is unlikely to be affected.

Who Should Take Precautions

Groups at risk include people with heart or lung disease, older adults, and children. These individuals are more likely to be affected by the presence of PM10 in the air.

What You Should Do

Members of sensitive groups should consider reducing prolonged or heavy exertion outdoors. The general public does not need to take special precautions and can continue with normal outdoor activities.

Source

EPA AirNow