Understanding long-term air quality trends has never been more important. Our historical AQI data spans over four decades, giving researchers, policymakers, urban planners, and public health professionals the comprehensive air quality record they need to make informed decisions.
What Is Historical AQI Data?
The Air Quality Index (AQI) is a standardized measure used to communicate how clean or polluted the air is at a given location. Historical AQI data captures those measurements over time, allowing users to identify trends, study the impact of environmental regulations, and assess community-level health risks. Our dataset draws from thousands of monitoring stations across the United States, providing county- and metro-level coverage for every year from 1980 to 2024.
What You Can Do With Historical AQI Data
With access to decades of air quality records, you can:
- Track pollution trends across decades to evaluate the effectiveness of the Clean Air Act and other regulations
- Compare regions to understand geographic disparities in air quality
- Support academic research in environmental science, epidemiology, and public policy
- Inform community advocacy with data-backed evidence about local air quality history
Data Coverage and Variables
Our historical AQI dataset includes median AQI, maximum AQI, days with unhealthy air quality, and breakdowns by pollutant type – including ozone, PM2.5, PM10, carbon monoxide, and nitrogen dioxide. Data is available at multiple geographic levels, making it flexible for both local and national analyses.
Get Instant Access to Historical AQI Data
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