AQI Alerts for Denver, CO

# HEADLINE -------------------- OZONE ACTION DAY ALERT FROM 400 PM SATURDAY UNTIL 400 PM SUNDAY # SUMMARY -------------------- The Colorado Department of Public Health and Environment has issued the following... WHAT...Ozone Action Day Alert. # DETAILS -------------------- WHERE Douglas, Jefferson, Denver, western Arapahoe, western Adams, Broomfield, Boulder, Larimer, and Weld Counties WHEN 400 PM Saturday July 11 to 400 PM Sunday July 12 IMPACTS Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot, dry, and stagnant weather will allow ozone to reach the Unhealthy for Sensitive Groups category on Saturday and Sunday. For Colorado air quality conditions, forecasts, and advisories, visit: https://www.colorado.gov/airquality/colorado\_summary.aspx If possible, please help us reduce ozone pollution by limiting driving gas and diesel-powered vehicles until at least 4 p.m. Sunday, July 12, 2026. Colorado is also addressing ozone pollution through state policies. For more information about health impacts and how ozone pollution forms in Colorado, visit: https://cdphe.colorado.gov/ozone- pollution-and-your-health HEALTH INFORMATION Increasing likelihood of respiratory symptoms and breathing discomfort in active children and adults and people with lung disease, such as asthma. Active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy outdoor exertion. ISSUED AT Saturday, July 11, 2026 at 4:10 PM MDT ISSUED BY Relayed by National Weather Service Boulder CO HEADER Air Quality Alert Message | Colorado Department of Public Health and Environment # AREAS AFFECTED -------------------- Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer, Weld