BREATHING EASY IN ARIZONA: WHAT TO KNOW ABOUT SUMMER AIR QUALITY
Most people who've lived in the Valley for a few years have made a kind of peace with summer. You know to stay inside during the afternoon. You know not to leave anything in the car. You've probably watched at least one haboob swallow the skyline from your window and waited it out.
What fewer people think carefully about is what's actually in the air on high-dust days, and what simple steps make the biggest difference — particularly for older adults, whose lungs and cardiovascular systems can be more sensitive to air quality changes.
This isn't only a story about dust storms. Arizona's air presents several distinct challenges across the months between May and September, and understanding them makes it easier to plan around them.
What's Actually in the Air
The most visible air quality event in a Valley summer is the haboob — a dust storm produced when desert sediment is sent airborne by the convective downdrafts of thunderstorms, typically developing southeast of Tucson and traveling northeast toward Phoenix, sometimes reaching walls over a kilometer in height. They're dramatic, and they're a genuine reason to stay indoors.
But the concern doesn't end when visibility returns. Dust particles can linger in the air for hours or even days after a storm passes. And the particles that matter most for health are the ones you can't see.
Air quality is measured using the Air Quality Index, or AQI. When the AQI falls between 100 and 150, people with lung disease, older adults, and children face greater risk from ozone exposure, and those with heart and lung disease face greater risk from particulate matter in the air.
There are two sizes of particulate matter relevant to breathing: PM10, which covers the larger visible dust from haboobs and construction sites, and PM2.5, the finer particles found in smoke and exhaust. Of the two, PM2.5 carries more health risk because particles that small bypass the body's natural filtration and reach deep lung tissue and the bloodstream.
Dust storms aren't the only source of poor air quality. Phoenix sun and triple-digit heat react with vehicle and industrial emissions to form ground-level ozone — a reaction that accelerates between 10 a.m. and 7 p.m., which is why the Maricopa County Air Quality Department issues most of its high-pollution advisories for afternoon hours from May through September. Wildfire smoke adds a third variable: California fires can push smoke east on summer westerlies, while Arizona forest fires send smoke south and west, especially during late spring before monsoon rains begin.
Why Older Adults Should Pay Attention
People most vulnerable to the impacts of air pollution include older adults, children, adults exercising outdoors, and people with heart or lung disease, asthma, or bronchitis. Exposure to ozone can increase the number and severity of asthma attacks, cause or aggravate bronchitis and other lung diseases, and reduce the body's ability to fight infection.
For someone already managing COPD, heart disease, or asthma, awareness of air quality conditions is a straightforward way to avoid triggering symptoms that might otherwise require medical attention. Most of the time, the protective steps are simple — and knowing when to take them is most of the work.
Valley Fever: A Local Risk Worth Knowing About
Valley fever — formally known as coccidioidomycosis — is a fungal infection caused by spores that live in the dry soil of the Southwest. When soil is disturbed, whether by a haboob, construction work, or yard activity, those spores can become airborne and be inhaled. The infection is often misdiagnosed without specific testing, simply because providers and patients don't always think to connect respiratory symptoms to dust exposure.
The good news is that most people who encounter the fungus never develop symptoms at all. For those who do, symptoms typically appear one to three weeks after exposure and include fatigue, cough, shortness of breath, headache, night sweats, and rash — similar enough to a summer cold that it's easy to wait out. Knowing to mention recent dust exposure to your doctor if those symptoms appear is usually all it takes to get the right test ordered.
Valley fever is most common among adults 60 and older, and those with diabetes or a weakened immune system face a higher risk of more serious illness. In Arizona, most cases are diagnosed between May and July, with a second peak in October through December — which maps closely onto monsoon season and the dust activity that follows. Awareness of that timing is a practical advantage.
What You Can Do
Check the AQI before making outdoor plans — not just the weather forecast. The Arizona Department of Environmental Quality posts daily air quality forecasts at azdeq.gov, and Maricopa County offers free email and text alerts through its air quality department. When the AQI reaches 101, sensitive groups — including adults over 65 and people with asthma, COPD, or heart disease — should reduce outdoor activity. When it reaches 151, everyone benefits from limiting time outside.
During dust storms, staying inside with windows and doors closed is the single most effective protective step available. Running a HEPA filter in the rooms where you spend the most time can meaningfully reduce indoor particulate exposure, especially on days when keeping windows shut limits natural air exchange. If your home has central HVAC, a MERV 13 filter captures wildfire smoke and fine PM2.5 particles effectively, and running the fan continuously during smoke events turns your system into a whole-home air cleaner.
If you use an inhaler for asthma or COPD, make sure it's accessible and hasn't been stored somewhere that gets hot — heat can degrade inhalers, and a high-AQI afternoon is exactly when you need your medication to work as expected.
If you garden, do yard work, or spend time near construction, consider wearing an N95 mask during those activities, particularly between May and July. Wetting the soil before digging can also reduce the release of spores into the air. These are small adjustments with meaningful payoff during peak season.
If flu-like respiratory symptoms develop after significant dust exposure and don't resolve within a week or two, mention the exposure to your doctor and ask about Valley fever testing specifically. It's a question Arizona providers are well-prepared to answer, and early detection makes treatment straightforward in the cases that need it.
Putting It in Perspective
Arizona's summer air quality is something most residents navigate without incident, year after year. The goal here isn't to add a new source of worry — it's to make the situation concrete enough that a few practical habits feel worth building. Checking the AQI, signing up for alerts, keeping a HEPA filter running on dusty days: none of this is complicated. It's the same kind of matter-of-fact preparation that Valley residents already bring to heat and water.
Knowing what to pay attention to, and when, is most of what good air quality management requires.
Resources
Aster's Outreach and Social Services team is here to help you connect with benefits, resources, and information that you need to live your best and budget better. Call 480-634-1659, email socialservices@asteraz.org, or fill out a brief interest form to book a free consultation.
The Arizona Department of Environmental Quality (azdeq.gov) publishes daily air quality forecasts for the Phoenix metro, including pollutant-specific readings and health guidance.
The Maricopa County Air Quality Department (maricopa.gov/1244/Air-Quality) offers free email and text alerts for high-pollution advisories and dust storm events.
The CDC's Valley Fever resources (cdc.gov/valley-fever) include symptom guides, risk factor information, and guidance on when to seek testing.
The American Lung Association's State of the Air report grades Maricopa County on ozone and particle pollution annually and identifies at-risk populations.
Sources
¹ American Lung Association. "Dust Storms." lung.org/clean-air/emergencies-and-natural-disasters/dust-storms.
² Maricopa County Air Quality Department. "Air Quality Index." maricopa.gov/1244/Air-Quality.
³ Arizona Department of Environmental Quality. "Phoenix Air Quality Forecast." azdeq.gov/forecast/phoenix.
⁴ Filterbuy. "Live Air Quality Index AQI Map Phoenix, AZ." filterbuy.com. (Citing EPA-certified monitoring data and Maricopa County Air Quality Department advisories.)
⁵ Centers for Disease Control and Prevention. "Valley Fever (Coccidioidomycosis)." cdc.gov/valley-fever. Last reviewed April 24, 2024.
⁶ Centers for Disease Control and Prevention. "Clinical Overview of Valley Fever." cdc.gov/valley-fever/hcp/clinical-overview/index.html. Last reviewed January 31, 2025.
⁷ Maricopa County. "Valley Fever." maricopa.gov/5813/Valley-Fever.
⁸ Lucio et al. "Haboob Dust Storms and Motor Vehicle Collision-related Trauma in Phoenix, Arizona." National Center for Biotechnology Information, PMC10393452.
⁹ ASU News. "What You Need to Know About Dust Storms and Valley Fever." news.asu.edu. August 28, 2025.
