Air Quality Alert: Denver-Boulder Reaches Very Unhealthy Levels for PM10

Air Quality high EPA · · Denver-Boulder, CO

On February 25, 2026, air quality in the Denver-Boulder area reached 'Very Unhealthy' levels, with PM10 recorded at an AQI of 287.

Current Air Quality

In the Denver-Boulder, CO reporting area, air quality observations for February 25, 2026, indicate significant concerns regarding particulate matter. The primary pollutant is PM10, which has reached an Air Quality Index (AQI) of 287, placing it in the “Very Unhealthy” category. Other measured pollutants include PM2.5 at an AQI of 64 (Moderate) and Ozone (O3) at an AQI of 38 (Good).

What This Means

An AQI of 287 is classified as “Very Unhealthy” by the EPA. This level indicates that the risk of health effects is increased for everyone, as air quality conditions are significantly degraded.

Who Should Take Precautions

While sensitive groups—including children, older adults, and people with heart or lung disease—are at the highest risk, the general public may also experience health effects when air quality reaches the “Very Unhealthy” level.

What You Should Do

To protect your health, the EPA recommends that everyone reduce outdoor physical activity. Sensitive groups should avoid all outdoor physical activity and move activities indoors or reschedule them to a time when air quality has improved. All others should avoid prolonged or heavy exertion and consider moving activities indoors.

Source

Data provided by EPA AirNow.

Source: EPA Official Notice