PHOENIX (April 23, 2025) Arizona’s 2025 State of the Air (SOTA) report released today shows Arizona’s ranking improved for year-round particle pollution for the period 2021–2023 as compared with last year’s report. However, more stagnant days and increased wildfire smoke continue to impact the state’s air quality. The Lung Association developed its annual SOTA report rankings using air quality data for the two most widespread pollutants in the United States: ozone and fine particulate matter. These pollutants pose a public health concern when they reach unhealthy levels.

Arizona faces unique air quality challenges, and the recent State of the Air findings highlight our progress and persistent concerns, said Daniel Czecholinski, ADEQ Air Quality Division Director. Though we’ve successfully cut emissions by 70 percent over three decades, western wildfire activity and stagnant weather continue to affect our air quality significantly. ADEQ remains dedicated to developing collaborative solutions with communities and stakeholders to safeguard public health.

Taking small actions through voluntary programs can add up to cleaner air for Arizona. See what you can do to improve air quality | Learn More >

Research shows that both ozone and particle pollution contribute to serious health conditions, including premature death, heart attacks, asthma attacks, and developmental issues, said JoAnna Strother, Senior Director of Advocacy for the American Lung Association in Arizona. Particle pollution can also cause lung cancer. To secure a healthier environment for residents and the millions who visit our beautiful state each year, we must continue to strengthen our collaborative efforts to improve air quality.

• American Lung Association State of the Air 2025 Report | View >

Ozone Levels

The SOTA 2025 report ranks the Phoenix metropolitan area 4th in the nation for unhealthy ozone days. Ground-level ozone pollution is created when nitrogen oxides (NOx) and volatile organic compounds (VOCs) chemically react in sunlight. On average, Arizona has more sunlight and less cloud cover than any other state in the nation. Phoenix, Tucson, and Yuma consistently rank at or near the top as the sunniest cities in the U.S., and this means more sunlight reaches the ground, giving ultraviolet radiation a greater chance to react and form more ozone. Compounds that form ozone also come from biomass (shrubs and trees), industry, wildfires, gas-powered garden equipment, and more.

Other contributors to ozone pollution in Arizona include emissions from international sources, such as Mexico and China, and other states, such as California. ADEQ is working with neighboring regions to better understand ozone transport and improve air quality for everyone.

In the Phoenix area, vehicles driving on the roads produce the majority of NOx and are the biggest contributor to man-made ozone. A major source of VOCs is vegetation. If there are enough VOCs present, it takes very little NOx to increase ozone levels. Because of the complexity of ozone formation, less NOx does not necessarily mean less ozone immediately.

Arizona motorists can improve air quality not only by driving or idling less but also by keeping vehicles tuned and operating within federal emissions limits. In addition, all Arizonans can help by choosing low-VOC plants for landscaping at homes and businesses.

• ADEQ Voluntary Vehicle Repair Program | View >
• Clean Air Make More Trees & Air Quality in Maricopa County | View >

To address rising ground-level ozone concentrations in Maricopa County and parts of Pinal County, ADEQ convened leading air quality experts in Arizona and across the nation. The Ground Level Ozone Research (GLOR) Project includes a team of distinguished scientists from the U.S. Environmental Protection Agency (EPA) (Region 9 and Office of Research and Development), NASA’s Jet Propulsion Laboratory, Maricopa County, the Maricopa Association of Governments (MAG), Arizona State University, and the University of Arizona.

The GLOR team will conduct field studies to verify emissions, model and predict ozone concentrations, and identify opportunities to mitigate high ozone levels, including developing potential incentives for ozone reduction strategies. See ADEQ press release about the project | View >

• Ozone Fact Sheet | View >
• EPA AQI Guide | View >

Particle Levels: PM_2.5

The SOTA 2025 report improved the national ranking for year-round particle pollution (PM_2.5) for the Phoenix metropolitan area from 9th place to 20th place.

During Arizona’s winter holiday season, the combination of smoke from burning wood in fire pits, fireplaces, and fireworks along with calm, cool weather can cause high levels of particulate matter pollution.

• Particulate Matter Fact Sheet | View >

By switching to propane instead of wood and reducing fireworks use, especially during calm winter conditions, we can reduce the air pollution that settles over valleys across Arizona during the holiday season.

ADEQ encourages Arizonans to stay informed about air quality conditions to protect their health and learn how everyday actions can improve air quality. ADEQ provides early forecasts for potential high-pollution days and ensures information about air quality and health remains clear and accessible to everyone.

• ADEQ Air Quality Forecasts | View >

Contacts

ADEQ Public Information Officer
Ph: 480-979-1600 (cell)
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