US Air Quality Index 2026: Live AQI for Every City

US Air Quality was created to make air quality data understandable and actionable for every American. While the EPA's AirNow system provides excellent raw data, interpreting AQI numbers and understanding what they mean for your daily activities can be confusing. Our platform bridges that gap by presenting air quality information in a clear, context-rich format that helps you make immediate decisions about outdoor exercise, commuting, school activities, and protecting vulnerable family members.

We cover hundreds of cities across all 50 states, providing AQI data that includes breakdowns by major pollutants: ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Each city page includes not just current readings but also historical trends, seasonal patterns, and health guidance specific to that location's typical pollution profile. A city in the Central Valley of California faces very different air quality challenges than a city on the coast of Maine, and our content reflects those regional differences.

Our health guidance sections are informed by EPA standards and public health research on air pollution exposure. We provide specific recommendations for sensitive groups including people with asthma, COPD, cardiovascular disease, elderly individuals, children, and pregnant women. Our activity guides help runners, cyclists, hikers, and outdoor workers understand when conditions are safe for prolonged exertion and when it is wise to move activities indoors. This practical, audience-specific guidance is what makes US Air Quality more than just a data dashboard.

Air quality in the United States is shaped by a complex interplay of industrial emissions, vehicle traffic, weather patterns, wildfires, and geography. In recent years, wildfire smoke has emerged as one of the most significant and unpredictable threats to air quality, affecting cities hundreds of miles from active fires. During major wildfire seasons, cities that typically enjoy excellent air quality can experience AQI readings in the unhealthy or even hazardous range for days or weeks at a time. Our seasonal guides and alert pages help you prepare for and respond to these events.

Ozone pollution continues to be a persistent challenge for many metropolitan areas, particularly during hot summer months. Ground-level ozone forms when pollutants from vehicles, power plants, and industrial facilities react with sunlight, making it a greater concern in warmer, sunnier regions. Our city pages highlight which pollutants are primary concerns for each location, so you can understand whether particulate matter or ozone is the bigger risk factor where you live and take appropriate precautions.

We also track the positive story of air quality improvement in the United States. Thanks to the Clean Air Act and continued regulatory efforts, many common air pollutants have decreased significantly over the past several decades. Lead, sulfur dioxide, and carbon monoxide levels have dropped dramatically, and many cities that once had severe smog problems now enjoy substantially cleaner air. Understanding these long-term trends provides important context for interpreting daily AQI readings and appreciating the value of continued environmental protection efforts.