About US Air Quality
US Air Quality provides free, accessible air quality information for cities across the United States. We aggregate official government data from the EPA and AirNow to help you understand local air quality conditions and make informed decisions to protect your health.
Our Mission
Air quality directly impacts the health of every American, yet accessing and understanding official air quality data can be challenging. The EPA publishes comprehensive air quality measurements, but the raw data can be difficult for everyday citizens to interpret and act upon.
US Air Quality exists to bridge this gap. Our mission is to make official EPA air quality data accessible, understandable, and actionable for everyone. We believe that every person deserves to know what they are breathing, whether the air in their community is safe, and what precautions they should take on high-pollution days.
We are committed to presenting air quality information in a clear, straightforward manner without sensationalism or unnecessary alarm. Our goal is to empower you with accurate information so you can make informed decisions about outdoor activities, travel, and protecting vulnerable family members.
Our Data Sources
We do not create air quality data or operate our own monitoring stations. All data on US Air Quality comes directly from official government sources maintained by the U.S. Environmental Protection Agency:
EPA AirNow
Our primary data source for real-time air quality information. AirNow is operated by the U.S. Environmental Protection Agency (EPA) in partnership with the National Oceanic and Atmospheric Administration (NOAA), National Park Service, NASA, Centers for Disease Control and Prevention (CDC), and state, tribal, and local air quality agencies across the country.
AirNow provides official Air Quality Index (AQI) values, individual pollutant measurements (PM2.5, PM10, Ozone, NO2, SO2, CO), air quality forecasts, and health guidance. The network includes over 2,000 monitoring stations nationwide.
Visit AirNow.gov →EPA Air Quality System (AQS)
The EPA Air Quality System is the official repository for ambient air quality data collected by the EPA, state, local, and tribal air pollution control agencies from thousands of monitors across the United States. This database contains decades of historical air quality measurements.
We use AQS data to provide historical trends, year-over-year comparisons, and long-term air quality analysis for each location. This helps users understand whether air quality in their area is improving or declining over time.
EPA Air Quality Data →Health Guidelines
All health recommendations on US Air Quality are based on official EPA guidance and the standardized Air Quality Index (AQI) developed by the EPA. The AQI is a nationally uniform index for reporting daily air quality that tells you how clean or polluted your air is and what associated health effects might be a concern.
We do not provide medical advice. We present the EPA's official health guidance for different AQI levels, including recommendations for sensitive groups such as people with asthma, heart disease, and the elderly.
Learn about AQI →How We Process and Present Data
Data Collection
We retrieve air quality data through the official AirNow API provided by the EPA. This API delivers real-time AQI values, pollutant concentrations, and forecast data directly from government monitoring stations. Our data pipeline processes this information and organizes it by geographic location to create our city and state pages.
Update Frequency
- Real-time AQI data: Updated hourly to match EPA AirNow update schedules
- Air quality forecasts: Updated twice daily when new EPA forecasts are issued
- Historical data: Updated annually when new EPA annual summary data is released
- Educational content: Reviewed quarterly to ensure alignment with current EPA guidelines
What We Present
- Current AQI and primary pollutant for each monitored location
- Individual pollutant readings (PM2.5, PM10, Ozone, NO2, SO2, CO) where available
- Air quality forecasts for the next 1-2 days
- Historical trends and year-over-year comparisons
- EPA health guidance based on current AQI levels
- City and state comparison tools
What We Do Not Do
- We do not create, modify, or estimate air quality measurements
- We do not operate our own air quality monitoring stations
- We do not provide medical diagnoses or treatment recommendations
- We do not make health claims beyond official EPA guidance
Who Benefits From This Data
Health-Conscious Individuals
People with respiratory conditions like asthma, COPD, or allergies can check air quality before outdoor activities. Parents can determine whether it is safe for children to play outside.
Outdoor Enthusiasts
Runners, cyclists, hikers, and athletes can plan outdoor workouts on days with good air quality and adjust their schedules when pollution levels are elevated.
Travelers and Relocators
People planning trips or considering moving to a new city can research typical air quality conditions and compare air quality between different locations.
Caregivers and Educators
School administrators, daycare providers, and caregivers for elderly individuals can make informed decisions about outdoor activities for vulnerable populations.
Researchers and Journalists
Environmental researchers and journalists can access historical air quality trends and compare data across different regions for reports and studies.
Community Advocates
Environmental justice advocates and community organizers can use air quality data to identify pollution disparities and advocate for cleaner air in their communities.
Who We Are
US Air Quality is an independent informational website operated by a small team of environmental data enthusiasts and web developers. We are not affiliated with the EPA, AirNow, NOAA, or any government agency. We do not receive government funding and are not a government contractor.
We built this site because we believe everyone deserves easy access to air quality information that affects their daily health decisions. While AirNow.gov provides excellent data, we saw an opportunity to present this information in a more user-friendly format with additional context for specific cities and regions.
Our role is to make official government data more accessible and easier to understand, not to replace it. For the most authoritative and up-to-the-minute information, we always recommend visiting AirNow.gov directly.
This website is supported by advertising revenue, which allows us to provide air quality information free of charge. Our editorial content is never influenced by advertisers, and we do not accept payment to feature specific locations or modify data presentation.
Important Limitations
While we strive to provide accurate and helpful air quality information, there are important limitations to understand:
- Monitor Locations: Air quality data comes from fixed monitoring stations. Actual air quality at your specific location may differ due to local sources of pollution, terrain, weather patterns, and distance from the nearest monitor.
- Data Latency: While we update data hourly, there may be brief delays between when the EPA publishes new readings and when they appear on our site. For critical decisions, verify with AirNow.gov directly.
- Coverage Gaps: Not all areas have air quality monitors. Rural areas may have limited or no monitoring coverage. The absence of data does not mean air quality is good or bad.
- Wildfire Events: During wildfire events, air quality can change rapidly and vary significantly over short distances. Real-time conditions may differ from reported values.
- Individual Sensitivity: The EPA's health guidance represents general recommendations. Individual sensitivity to air pollution varies based on age, health conditions, and other factors.
Health Information Disclaimer
This website provides general information about air quality based on EPA data and guidance. It is not intended as medical advice and should not be used as a substitute for professional medical consultation.
If you have respiratory conditions such as asthma or COPD, heart disease, or other health concerns, please consult with a healthcare provider for personalized guidance on how air quality may affect you and what precautions you should take.
Sensitive groups, including children, the elderly, pregnant women, and people with pre-existing health conditions, may be affected by air pollution at lower levels than the general population. Always err on the side of caution and consult your healthcare provider if you have concerns.
Editorial Policy
Data Accuracy: We strive to present EPA data accurately and without modification. Our data pipeline is monitored for errors, and we regularly audit our displayed values against source data. If you notice any discrepancies, please contact us immediately.
Update Schedule: Real-time air quality data is updated hourly. Air quality forecasts are updated twice daily. Historical data is updated annually. Educational content is reviewed quarterly to ensure it reflects current EPA guidelines and scientific understanding.
Editorial Independence: We do not accept payment to feature specific content, modify data presentation, or publish favorable information about any location. Our editorial decisions are based solely on providing accurate, helpful information to users.
Corrections Policy: If we discover an error in our data or content, we correct it promptly. Significant corrections are noted on the affected page with the date of correction.
Affiliate Disclosure: This website may contain affiliate links to air quality monitors, air purifiers, or related products. These relationships are clearly disclosed and never influence our data presentation or editorial content.
Contact Us
Have questions about our data, found an error, or want to provide feedback? We would love to hear from you. Our team reviews all inquiries and strives to respond within 2-3 business days.
Get in Touch