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Daily Maximum Eight-Hour Ozone Averages for September 2021

The table below lists the peak daily maximum eight-hour ozone concentrations measured in September 2021 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.) All ozone measurements are in parts per billion.

Use the selection boxes below to customize this report. You may select a different month, a different year, a different report format, and whether or not to include time on the report. Click on the Generate Report button once you have made your selections.

Month:Year:Report Format: Include time:
Include time
Highlight with AQI colors
AreaMonitoring SitePOCSeptember 2021POCMonitoring Site
North West
Hammond-141st St137373936484346383438505249453754544655NA1Hammond-141st St
Ogden Dunes139413637534149423637515448494053545052NA1Ogden Dunes
Michigan City-W. Michigan Blvd139404439574049423440505253483754674852NA1Michigan City-W. Michigan Blvd
LaPorte-E. Lincolnway138384236494449423337495149463749505451NA1LaPorte-E. Lincolnway
AreaMonitoring SitePOCSeptember 2021POCMonitoring Site
North Central
South Bend-Shields Dr137404638464247403338464946403651515150NA1South Bend-Shields Dr
Potato Creek State Park138414035474347423536465042433750485546NA1Potato Creek State Park
Granger-Beckley St137394639454147413439475048413648514850NA1Granger-Beckley St
AreaMonitoring SitePOCSeptember 2021POCMonitoring Site
North East
Fort Wayne-Beacon St137424440444449433642504749363746425148NA1Fort Wayne-Beacon St
Leo HS138414443434551393742545150393946455151NA1Leo HS
AreaMonitoring SitePOCSeptember 2021POCMonitoring Site
West Central
Terre Haute-Lafayette Ave143404425404451403540494844323847424946NA1Terre Haute-Lafayette Ave
West Union141404423384552403437484742333845393939NA1West Union
AreaMonitoring SitePOCSeptember 2021POCMonitoring Site
East Central
Anderson-Eastside Elem. School242414536434555413845515352373646495049NA2Anderson-Eastside Elem. School
Indpls-Washington Park1444248324346544341435250463238NVNANANANA1Indpls-Washington Park
Indpls-Harding St144444732434450413838494942293843405950NA1Indpls-Harding St
Indpls-Ft. Harrison144414932424755424045525148343744515153NA1Indpls-Ft. Harrison
Noblesville-191st St144424831444557443847535150353745534950NA1Noblesville-191st St
Indpls - I-70 E135364631384352323140494642303142405350NA1Indpls - I-70 E
Kokomo - E. Vaile Ave.140424834504651413947505147364048445852NA1Kokomo - E. Vaile Ave.
AreaMonitoring SitePOCSeptember 2021POCMonitoring Site
South West
Evansville-Buena Vista Rd144475237384349413641414235303935323222NA1Evansville-Buena Vista Rd
St. Philips145485735394652453843474638333836333423NA1St. Philips
AreaMonitoring SitePOCSeptember 2021POCMonitoring Site
South East
New Albany139505142324649443843434142304136394331NA1New Albany
Charlestown State Park138474346344557443843454343343736364030NA1Charlestown State Park
POC (Parameter Occurrence Code): a code used to correctly separate data from multiple instruments at one site.
NV - There are not enough valid eight-hour averages for this day (there must be eighteen valid eight-hour averages).
NA - Data not available.

Interpreting the AQI

Air Quality Index

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 EPA's AirNow web site.

Place your mouse pointer over the scale displayed above to view information about the Air Quality Index, and each of the rating levels.

The actual index calculation is different for each parameter measured and is specified by the EPA. The following table shows the various breakpoints used in calculating the AQI.

AQI Breakpoint Definitions
AQI Range 1hr Ozone
in ppm
8hr Ozone
in ppm
0 - 50 Not Defined 0 - 0.054
51 - 100 Not Defined 0.055 - 0.070
101 - 150 0.125 - 0.164 0.071 - 0.085
151 - 200 0.165 - 0.204 0.086 - 0.105
201 - 300 0.205 - 0.404 0.106 - 0.200
301 - 400 0.405 - 0.504 0.201 - 0.2011
401 - 500 0.505 - 0.604 Not Defined
500+ Not Defined Not Defined

PLEASE NOTE: This data has not been verified by the IDEM and may change. This is the most current data, but it is not official until it has been certified by our technical staff. Data is collected from IDEM ambient monitoring sites and may include data collected by other outside agencies. This data is updated hourly. All times shown are in local standard time unless otherwise indicated.