Four Highest Eight-Hour Ozone Concentrations in 2018
as of April 22

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 2018 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.

Year	Report Format
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018	Tabular (Web Formatted) Comma-Delimited
Highlight with AQI colors

Area	Monitoring Site	POC	Highest			Second Highest			Third Highest			Fourth Highest
			Date	Time	Value	Date	Time	Value	Date	Time	Value	Date	Time	Value
North West
	Hammond-141st St	1	04/06/2018	1100	44	03/11/2018	1000	44	04/12/2018	0700	42	04/10/2018	1000	42
	Ogden Dunes	1	04/19/2018	1300	56	04/20/2018	0900	50	04/12/2018	0900	49	04/08/2018	1000	49
	Michigan City-W. Michigan Blvd	1	04/19/2018	1400	58	04/20/2018	0900	55	04/21/2018	1400	51	04/17/2018	1100	50
	Valparaiso	1	04/19/2018	1100	52	04/12/2018	0900	51	04/20/2018	0900	47	04/10/2018	0900	47
	Gary-IITRI	1	04/19/2018	1300	55	04/21/2018	1600	49	04/20/2018	1100	49	04/17/2018	1200	49
	LaPorte-E. Lincolnway	1	04/19/2018	1300	55	04/12/2018	0900	52	04/20/2018	0900	51	03/15/2018	0700	50
North Central
	South Bend-Shields Dr	1	04/20/2018	1100	51	04/19/2018	1300	51	04/12/2018	1000	51	04/21/2018	1100	49
	Bristol	1	04/12/2018	1100	52	04/21/2018	1100	51	04/19/2018	1300	51	04/20/2018	1100	50
	Potato Creek State Park	1	04/12/2018	1100	54	04/19/2018	1000	53	04/20/2018	1000	51	04/08/2018	1100	51
	Granger-Beckley St	1	04/19/2018	1300	52	04/12/2018	1100	52	04/20/2018	1000	51	04/21/2018	1100	49
North East
	Fort Wayne-Beacon St	1	04/12/2018	1100	54	04/19/2018	1000	51	04/20/2018	1100	50	04/13/2018	0900	50
	Leo HS	1	04/12/2018	1200	54	04/13/2018	1000	52	04/19/2018	1000	51	04/20/2018	1000	50
	Roanoke Elem. School	1	04/19/2018	0900	50	04/21/2018	1000	49	04/20/2018	1200	49	03/15/2018	1000	44
West Central
	Terre Haute-Lafayette Ave	1	04/12/2018	1200	58	04/21/2018	1000	55	04/17/2018	1100	53	03/25/2018	1200	50
	Flora	1	04/20/2018	1000	50	04/19/2018	1000	50	04/21/2018	1000	49	04/12/2018	1100	48
	Sandcut	1	04/12/2018	1200	59	04/21/2018	1100	57	04/17/2018	1200	54	04/19/2018	1100	51
	West Union	1	04/12/2018	0900	57	04/21/2018	0900	56	04/17/2018	1000	54	04/19/2018	1000	51
East Central
	Emporia	1	04/12/2018	1100	58	04/21/2018	1000	52	04/13/2018	0900	52	04/19/2018	1000	51
	Albany	1	04/12/2018	1100	60	04/13/2018	0900	53	04/19/2018	1000	51	03/15/2018	1100	49
	Indpls-Washington Park	1	04/12/2018	1000	54	04/21/2018	1100	53	04/19/2018	1100	50	04/20/2018	1000	49
	Indpls-Harding St	1	04/12/2018	1100	58	04/21/2018	1100	57	04/20/2018	1100	51	04/19/2018	1100	50
	Indpls-Ft. Harrison	1	04/12/2018	1100	58	04/21/2018	1100	56	04/20/2018	1100	53	04/19/2018	1100	53
	Monrovia	1	04/12/2018	1100	55	04/21/2018	1000	52	04/19/2018	1100	49	04/17/2018	1100	49
	Whitestown	1	04/12/2018	1100	56	04/21/2018	1000	54	04/19/2018	1100	51	04/20/2018	1000	49
	Avon	1	04/12/2018	1100	56	04/21/2018	1100	52	04/20/2018	1200	49	04/19/2018	1100	49
	Fairland	1	04/12/2018	1100	58	04/13/2018	0800	51	04/19/2018	1100	50	03/15/2018	1000	49
	Noblesville-191st St	1	04/12/2018	1100	57	04/21/2018	1100	51	04/13/2018	0800	51	04/19/2018	1100	50
	Hope	1	04/12/2018	1100	58	04/21/2018	0900	55	04/17/2018	1100	53	04/13/2018	0900	53
	Indpls - I-70 E	1	04/12/2018	1100	53	04/21/2018	1000	50	04/13/2018	0700	49	04/08/2018	1300	46
	Kokomo - E. Vaile Ave.	1	04/12/2018	1100	55	04/19/2018	1000	50	03/15/2018	1000	50	04/20/2018	1100	49
	Helmsburg	1	04/21/2018	1000	56	04/17/2018	1100	54	04/19/2018	1200	53	04/20/2018	1000	52
South West
	Boonville	1	03/15/2018	1100	63	04/21/2018	1000	59	04/18/2018	1000	55	04/17/2018	1000	55
	Evansville-Buena Vista Rd	1	03/15/2018	1000	61	04/21/2018	1000	57	04/18/2018	1000	55	04/12/2018	1000	53
	Inglefield	1	03/15/2018	1100	60	04/21/2018	1000	58	04/12/2018	1100	55	04/18/2018	1000	54
	St. Philips	1	03/15/2018	1100	64	04/21/2018	1000	57	04/18/2018	1000	57	04/12/2018	1100	56
	Leopold	1	03/15/2018	1200	64	04/21/2018	1200	61	04/17/2018	1100	57	04/12/2018	1100	57
	Dayville	1	03/15/2018	1100	60	04/21/2018	1000	55	04/18/2018	1000	53	04/17/2018	1000	52
	Plummer	1	04/21/2018	1100	56	04/12/2018	1000	55	04/20/2018	1100	52	04/17/2018	1200	52
South East
	New Albany	1	04/21/2018	1100	58	04/17/2018	1200	55	04/12/2018	1200	55	03/15/2018	1100	54
	Charlestown State Park	1	04/21/2018	1000	58	04/17/2018	1100	57	04/13/2018	0900	55	04/12/2018	1200	55
	Brownstown	1	04/12/2018	1000	55	04/21/2018	1000	52	04/19/2018	1300	51	04/17/2018	1200	51
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 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

• The AQI for ozone is based on either the peak eight-hour running average since midnight OR the peak one-hour measurement since midnight.

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.