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Air Quality Alert Message

Status

Issued Active alert

Start Time

Tue 08/18/2026 06:10 PM EDT

End Time

Wed 08/19/2026 06:00 PM EDT

Impacts

Informational

Full Alert Message

Air Quality Alert Message Colorado Department of Public Health and Environment Relayed by National Weather Service Boulder CO 410 PM MDT Tue Aug 18 2026 ...OZONE ACTION DAY ALERT FROM 400 PM TUESDAY UNTIL 400 PM WEDNESDAY... 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 Tuesday August 18 to 400 PM Wednesday August 19 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot and sunny weather with light winds and limited potential for afternoon storms will allow ozone to reach levels that are Unhealthy for Sensitive Groups on Tuesday and Wednesday. The highest ozone concentrations are most likely in the 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. Wednesday, August 19, 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.

Technical Header

COC014-013-035-069-059-123-031-001-005-192200- Broomfield-Boulder-Douglas-Larimer-Jefferson-Weld-Denver- Adams-Arapahoe- 410 PM MDT Tue Aug 18 2026