...OZONE ACTION DAY ALERT FROM 400 PM THURSDAY UNTIL 400 PM FRIDAY... 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 Thursday August 20 to 400 PM Friday August 21 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot, sunny, and stagnant weather will allow ozone to reach the Unhealthy for Sensitive Groups concentration on Thursday and Friday. The highest concentrations are expected in southern and western portions of the Denver Metro Area. 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. Friday, August 21, 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.