Air Quality Alert: Denver-Boulder Area Reaches Unhealthy for Sensitive Groups Level
Areazine synthesizes this EPA air-quality advisory directly from EPA's official public data feed. See our methodology for full source attribution and refresh cadence.
On March 20, 2026, air quality in the Denver-Boulder area reached an AQI of 128, categorized as Unhealthy for Sensitive Groups due to PM10 levels.
What this EPA air-quality advisory tells you, and what most readers miss
This notice was issued by EPA on April 5, 2026 and geographically references Denver-Boulder, CO. Its severity classification of "low" signals how the issuing agency weighs the risk of harm if no action is taken - "critical" and "high" tier alerts typically carry direct consumer actions, while "medium" and "low" tend toward informational guidance or monitoring advisories. The category it belongs to - Air Quality - determines the informational context it sits in, and which agency or body is the authoritative source for updates.
Most readers skim a notice like this, check whether they are personally affected, and move on. The more useful lens is to verify its scope, source, and timestamp, then compare related notices without assuming that one record proves a broader trend.
Areazine pairs this record with the original agency URL so you can check the primary source before acting. Its related labels are air-quality, epa, aqi, Denver-Boulder.
Current Air Quality
The Denver-Boulder area in Colorado reported an Air Quality Index (AQI) of 128 on March 20, 2026. The primary pollutant of concern is PM10, which has reached the "Unhealthy for Sensitive Groups" category. Other readings for the area include PM2.5 at an AQI of 70 (Moderate) and Ozone (O3) at an AQI of 47 (Good).
What This Means
An AQI level of 128 is classified by the EPA as "Unhealthy for Sensitive Groups." This category indicates that air quality is reaching levels where members of sensitive groups may experience health effects, though the general public is less likely to be affected.
Who Should Take Precautions
Groups at increased risk from this level of particle pollution include people with heart or lung disease, older adults, children, and teenagers. These individuals should be mindful of their outdoor activities while these conditions persist.
What You Should Do
Members of sensitive groups should reduce prolonged or heavy exertion outdoors. It is recommended to take more breaks and engage in less intense outdoor activities. Watch for symptoms such as coughing or shortness of breath. The general public can continue normal outdoor activities.
Source
Data provided by EPA AirNow.
Original source: EPA Official Notice ↗
Related Air Quality
All Air Quality →Frequently Asked Questions
Common questions about this EPA air-quality advisory.