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 17 to 400 PM Saturday July 18 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot and sunny weather will result in concentrations of ozone reaching the Unhealthy for Sensitive Groups category on Friday and Saturday. The highest concentrations are most likely in the western portions of the Denver Metro area, 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, July 18, 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.

* WHAT...High temperatures between 99-102 expected. Low temperatures Sunday night will be between 69-71 in the Denver metro. * WHERE...Fort Collins, Boulder and the western suburbs of Denver, Denver, and Greeley. * WHEN...From 10 AM Sunday to 9 PM MDT Monday. * IMPACTS...Hot temperatures may cause heat illnesses.