Where can I find historical or archived data?

On the AirData website

AirData provides detailed and summary data, plus reports, maps, and other displays:


On the AirNow website

Past data for a monitor:

  • Under the Maps & Data dropdown header, select Historical Data – by Monitor.
  • Or, on the Interactive Map, use the Animations tab (shows the last 24 hours) or the Archive tab (shows yesterday and other past days).

Past data for an area (city):

  • Check the bar chart in the Current Air Quality section of the AirNow home page. The default is "day," which shows every hour since midnight. Click the buttons for "week" or "month" to see an AQI for the each of the past 7 or 30 days.
  • Under the Maps & Data dropdown header, select Past Data – by City.
  • Or, select the Historical Air Quality tab on any state page.