Notes on Air Quality Metrics in Eugene/Springfield
You’ve probably discovered this page http://www.lrapa.org/216/Todays-Current-Air-Quality. The gauges in the widget http://widgets.lrapa.org/ show weighted averages:
“The current AQI represents the amount of pollution in the air using a weighted average of the last twelve hours and is a forecast of the current days average pollution level.”
For more detailed information see this link http://aqicn.org/city/usa/oregon/eugene-amazon-park/. This differentiates between the readings at Amazon Park, Highway 99, and Springfield City Hall.
As of 10:00 am, the AQI is 182 at Amazon and 434 in Springfield.
For a nice color coded map of Oregon, see AirNow.gov