× Air Quality Alert
Until 2025-06-22T00:00:00-06:00 • National Weather Service
The Colorado Department of Public Health and Environment has issued the following... WHAT...Ozone Action Day Alert. WHERE...Douglas, Jefferson, Denver, western Arapahoe, western Adams, Broomfield, Boulder, Larimer, and Weld Counties WHEN...400 PM Saturday June 21 to 1200 AM Sunday June 22 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot and stagnant weather conditions will result in ozone concentrations reaching the Unhealthy for Sensitive Groups category Saturday afternoon and evening. These elevated ozone readings will be most likely for northern parts of the Denver metro area, northward to including Boulder, Ft. Collins, Greeley, and the foothills to the west of these locations. Improving, lower ozone levels are expected on 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 midnight, Saturday night, June 21, 2025. 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.