...OZONE ACTION DAY ALERT FROM 400 PM FRIDAY UNTIL 400 PM SATURDAY... 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 Friday July 31 to 400 PM Saturday August 01 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Ozone is expected to reach the Unhealthy for Sensitive Groups category on Friday and Saturday. The highest concentrations are most likely in the western portions of the northern Colorado Front Range, including the lower foothills. 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. Saturday, August 1, 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.