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 Sunday July 13 to 400 PM Monday July 14 IMPACTS. Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot and stagnant weather will allow ozone to reach the Unhealthy for Sensitive Groups category on Sunday and Monday. The highest concentrations are expected in western portions of the Denver Metro area, and northward along the I-15 corridor towards Fort Collins. 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. Monday, July 14, 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.
