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Outdoor Air Quality Data

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Air Data - Daily Air Quality Tracker (PDF Report)

Use of AirNow Data

This plot provides ozone and PM2.5 data from AirNow for recent days that are not available from AQS. AQS data, as it becomes available, replaces any AirNow data. The AirNow data are not fully verified and validated through the quality assurance procedures monitoring organizations use to officially submit and certify data on the EPA AQS (Air Quality System) and, therefore, cannot be used to formulate or support regulation, guidance or any other Agency decision or position.

This 2020 data report puts multiple AirData outputs on a single page to show:

  • Daily AQI values in 2020 relative to the previous 20-year high and low and the previous five-year average
  • Counts of "good" and "bad" AQI days in 2020 relative to the previous 20-year high and low and the previous five-year average
  • Distribution of daily AQI values in 2020 by calendar quarter relative to previous years

More information: The most recent AQI values are based on available ozone and PM2.5 data from AirNow (see "Use of AirNow Data" info box).  The 20-year high/low backdrop is based on AQS data from 2000-2019.  It shows the range of the highest and lowest daily max AQI values on each date.  The 5-year average is based on AQS data from 2015-2019.  It  shows the average of daily max AQI values on each date. The distribution plots fit a normal density function to the data to convey spread and central tendency in each quarter relative to the same quarter in other years. In the tile plot, each tile represents one day and is color-coded based on the AQI level for that day.


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Air Data