Ozone Advisory Issued for Maricopa County: August 19-20, 2026

High Pollution Alert Issued for Maricopa County Amid Rising Ozone Levels

The Arizona Department of Environmental Quality (ADEQ) has announced an Ozone High Pollution Advisory for Maricopa County, effective Wednesday, August 19, and Thursday, August 20, 2026. This advisory comes as ozone concentrations are anticipated to surpass federal health standards.

Ozone at ground level is produced when vehicle emissions, industrial activities, and various chemical processes interact with sunlight, especially during spring and summer. This pollutant can adversely affect lung function and exacerbate asthma, posing a risk to all residents, particularly children, older adults, and those with existing respiratory conditions.

Recommended Actions for Residents and Businesses

To mitigate ozone pollution, ADEQ and the Maricopa County Air Quality Department (MCAQD) suggest several measures:

Encourage remote work to minimize traffic.

Reduce car usage by carpooling, vanpooling, or utilizing public transport.

Avoid drive-thru lines by opting to park and go inside.

Consider walking or biking for short trips.

Use a broom instead of a leaf blower for yard work.

Refuel vehicles after dark or in the cooler evening hours.

Opt for low-VOC or water-based paints and stains.

Delay painting projects until the advisory is lifted.

Ensure that containers with household chemicals are well-sealed to prevent evaporation.

Visit Maricopa.gov/AQ for more tips on reducing air pollution.

Activity Restrictions During the Advisory

The advisory includes specific restrictions to reduce pollution:

Prohibition of wood burning in residential and outdoor fireplaces, fire pits, and chimeneas.

Government employees and contractors should refrain from using leaf blowers, and residents are encouraged to do the same.

Avoidance of off-road vehicle use.

Understanding the High Pollution Advisory

A High Pollution Advisory alerts the public when air pollutants are expected to exceed safe levels. Ground-level ozone forms through chemical reactions involving sunlight, nitrogen oxides, and volatile organic compounds (VOCs).

About Maricopa County Air Quality Department

The MCAQD is dedicated to enhancing air quality in Maricopa County for a healthier living environment. Governed by the Maricopa County Board of Supervisors, the department adheres to the standards of the federal Clean Air Act. For more information, visit Maricopa.gov/AQ.

Stay updated with MCAQD on social media: Instagram, Twitter, and Facebook.

Download the MCAQD’s Clean Air app for iOS and Android to access air quality information on the go.