* Although preliminary annual statistics are continually released, SAGE Stats only provides final statistics, which are released in May of the following year. Report includes exceptional events; these events (such as wildfires) are not "reasonably controllable" and are hence excluded from assessments relating to air quality regulation, but they nevertheless affect air quality.
Years Available: 2000–2019
Permanent Link: http://data.sagepub.com/sagestats/4033
General Notes: *Median value shows the 50th percentile of counties reporting data to the AQSData Mart; it is not reflective of the entire country. **PM2.5 - Particulate Matter smaller than 2.5 micrometers. Daily average concentrations measured by monitoring equipment and reported to AQS. The 98th percentile 24-hour value, in micrograms per cubic meter. This value is higher than 98 percent of 24-hour values for the year.