Four Highest Eight-Hour Ozone Concentrations in 2017
as of October 23

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 2017 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	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	07/18/2017	1100	83	06/15/2017	1100	75	06/02/2017	1000	72	06/09/2017	1000	69
	Ogden Dunes	1	06/09/2017	1100	80	07/18/2017	1000	79	06/13/2017	0900	72	06/02/2017	1000	72
	Michigan City-W. Michigan Blvd	1	06/09/2017	1100	84	06/13/2017	1000	80	06/04/2017	1200	79	06/15/2017	1100	77
	Valparaiso	1	06/09/2017	1100	81	06/03/2017	1000	78	07/18/2017	0900	77	06/15/2017	1100	77
	Gary-IITRI	1	07/18/2017	1000	79	06/09/2017	1100	77	06/02/2017	1000	75	06/03/2017	0900	70
	LaPorte-E. Lincolnway	1	07/18/2017	1000	81	06/09/2017	1100	80	06/03/2017	1000	73	07/19/2017	0900	72
North Central
	South Bend-Shields Dr	1	06/09/2017	1200	80	07/06/2017	1100	73	06/10/2017	1300	73	06/03/2017	1100	72
	Bristol	1	06/09/2017	1200	72	07/06/2017	1100	67	06/10/2017	1400	67	06/03/2017	1000	64
	Potato Creek State Park	1	06/09/2017	1300	79	07/19/2017	1100	69	06/10/2017	1400	68	06/03/2017	1000	68
	Granger-Beckley St	1	06/09/2017	1200	77	07/18/2017	1200	70	06/10/2017	1400	70	07/06/2017	1000	68
North East
	Fort Wayne-Beacon St	1	06/10/2017	1200	71	06/03/2017	1000	69	05/16/2017	1100	65	09/23/2017	1100	62
	Leo HS	1	06/10/2017	1300	72	06/03/2017	1000	70	05/16/2017	1200	68	06/11/2017	1100	64
	Roanoke Elem. School	1	06/10/2017	1200	70	06/03/2017	1000	67	05/16/2017	1200	65	06/11/2017	1100	61
West Central
	Terre Haute-Lafayette Ave	1	06/05/2017	1200	72	06/10/2017	1000	71	06/16/2017	1200	69	06/09/2017	1100	68
	Flora	1	06/09/2017	1100	63	06/04/2017	1100	62	06/15/2017	1200	61	05/16/2017	1000	61
	Sandcut	1	06/10/2017	1000	71	06/05/2017	1200	71	06/09/2017	1200	68	09/23/2017	1000	66
	West Union	1	06/05/2017	1100	71	06/02/2017	1000	69	06/10/2017	0800	68	06/09/2017	1000	67
East Central
	Indpls-E.16th St	1	06/04/2017	1100	71	06/10/2017	1000	69	06/03/2017	1100	69	06/02/2017	1100	69
	Emporia	1	06/03/2017	1000	72	06/02/2017	1200	70	06/21/2017	1200	68	06/10/2017	0900	68
	Albany	1	06/03/2017	1100	74	06/10/2017	1000	70	06/09/2017	1200	68	06/04/2017	0800	63
	Indpls-Washington Park	1	06/04/2017	1000	68	06/10/2017	1000	67	06/05/2017	1100	67	06/03/2017	1100	67
	Indpls-Harding St	1	06/04/2017	1100	67	06/10/2017	1000	65	06/05/2017	1200	65	06/09/2017	1200	64
	Indpls-Ft. Harrison	1	06/04/2017	1100	71	06/02/2017	1100	71	06/03/2017	1000	70	06/10/2017	1000	68
	Monrovia	1	09/23/2017	1000	59	06/09/2017	1400	59	06/10/2017	1100	58	06/05/2017	1200	58
	Trafalgar	1	06/09/2017	1200	64	06/05/2017	1300	64	06/10/2017	1000	63	05/16/2017	1100	63
	Whitestown	1	06/10/2017	1100	71	06/05/2017	1100	69	06/04/2017	1100	66	06/03/2017	1000	66
	Avon	1	09/23/2017	1000	68	06/10/2017	1000	68	06/04/2017	1100	68	06/05/2017	1200	67
	Fairland	1	06/02/2017	1200	73	06/10/2017	1000	69	06/09/2017	1300	69	06/04/2017	1000	69
	Noblesville-191st St	1	06/10/2017	1000	72	09/26/2017	1100	71	06/03/2017	1000	69	06/02/2017	1100	69
	Hope	1	06/09/2017	1200	68	05/15/2017	1000	67	06/10/2017	0900	65	06/16/2017	1000	64
	Indpls - I-70 E	1	06/10/2017	1100	67	06/04/2017	1100	65	06/03/2017	1200	65	05/15/2017	1200	63
	Helmsburg	1	06/09/2017	1100	67	06/10/2017	1100	65	06/02/2017	1000	62	05/14/2017	1100	62
South West
	Boonville	1	06/02/2017	1000	74	06/03/2017	1000	73	05/15/2017	0900	71	06/09/2017	1000	68
	Evansville-Buena Vista Rd	1	06/02/2017	1000	71	06/03/2017	1000	70	06/09/2017	1100	67	05/15/2017	0900	64
	Lynnville	1	06/02/2017	1100	69	06/03/2017	1000	67	06/09/2017	1000	66	06/16/2017	1000	64
	Inglefield	1	06/02/2017	1000	75	06/03/2017	1000	71	06/09/2017	1000	68	05/15/2017	0900	68
	St. Philips	1	06/02/2017	1000	78	06/03/2017	1000	73	06/09/2017	1000	69	05/14/2017	0900	68
	Leopold	1	06/03/2017	0900	71	06/09/2017	1100	69	05/14/2017	1000	68	05/15/2017	0900	66
	Dayville	1	06/02/2017	1000	74	06/03/2017	1000	73	06/09/2017	1000	68	05/15/2017	0900	68
	Plummer	1	05/15/2017	1100	71	06/04/2017	1100	70	06/09/2017	1100	69	06/05/2017	1300	67
South East
	New Albany	1	06/04/2017	1000	75	06/03/2017	1100	75	07/17/2017	1200	74	06/16/2017	1100	74
	Charlestown State Park	1	06/03/2017	1100	71	06/04/2017	1000	70	05/15/2017	1000	70	06/16/2017	1200	68
	Brownstown	1	06/03/2017	1100	68	06/09/2017	1200	66	05/15/2017	1100	65	06/04/2017	0900	63
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.