Home About Calendar Contact Grants & Loans Records
IDEM HomeAir Home
Four Highest Eight-Hour Ozone Concentrations in 2009
Use this form to retrieve the four highest eight-hour ozone concentration averages from data collected at IDEM monitoring sites beginning December 14, 2005 through today. Although this is our most current data, it is not considered official until it has been certified by our technical staff. This information is updated hourly. All times shown are in Local Standard Time.

The table below lists the four highest daily maximum eight-hour ozone concentrations measured in 2009 in each community where the IDEM measures ozone. Concentrations that are rated Moderate or higher are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.) The fourth-highest average is in bold black (unless it is highlighted). All ozone measurements are in parts per billion. Times are shown in 24-hour format and correspond to the beginning of the eight hour average.

Use the selection boxes below to customize this report. You may select a different year or a different report format. If you want to cut and paste data from this web page into another application, such as a spreadsheet, select the comma-delimited format. Click on the Generate Report button once you have made your selections.

YearReport Format
Highlight with AQI colors
AreaMonitoring SitePOCHighestSecond HighestThird HighestFourth Highest
DateTimeValueDateTimeValueDateTimeValueDateTimeValue
POC (Parameter Occurrence Code): a code used to correctly separate data from multiple instruments at one site.

Interpreting the AQI

Each NAAQS pollutant has a separate AQI scale, with an AQI rating of 100 corresponding to the concentration of the Federal Standard for that pollutant. Additional information about the AQI and how it can be used is available from the EPAExit.

The AQI scale is divided into the following categories:

Air Quality
GoodModerateUnhealthy
(for sensitive groups)
UnhealthyVery UnhealthyHazardous
The AQI Air Quality Scale