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Air Quality Alert Message

Status

Issued Active alert

Start Time

Mon 07/20/2026 06:10 PM EDT

End Time

Tue 07/21/2026 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 Mon Jul 20 2026 ...OZONE ACTION DAY ALERT FROM 400 PM MONDAY UNTIL 400 PM TUESDAY... 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 Monday July 20 to 400 PM Tuesday July 21 IMPACTS...Ozone Action Day Alert is now in effect for the Front Range Urban Corridor. Hot and stagnant weather conditions will result in ozone concentrations reaching the Unhealthy for Sensitive Groups category both Monday and Tuesday during the afternoon and evening hours. 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. Tuesday, July 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.

Technical Header

COC035-014-001-069-013-005-059-031-123-212200- Douglas-Broomfield-Adams-Larimer-Boulder-Arapahoe-Jefferson- Denver-Weld- 410 PM MDT Mon Jul 20 2026