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Four Highest Eight-Hour Ozone Concentrations in 2018
as of September 19

Use this form to retrieve the four highest eight-hour ozone concentration averages from data collected at TCEQ 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 TCEQ 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
Area Monitoring Site POC Highest Second Highest Third Highest Fourth Highest
Date Time Value Date Time Value Date Time Value Date Time Value
Dallas-Fort Worth
Ft. Worth Northwest C13/AH302 205/17/201811008307/25/201811008107/23/201810007604/24/2018120076
Keller C17207/25/201812009105/17/201811008508/02/201812008308/03/2018100078
Frisco C31/C680107/28/201810008507/26/201812008405/26/201811008105/07/2018120081
Midlothian OFW C52/A137107/23/201810007404/24/201812007308/21/201812007208/01/2018110068
Denton Airport South C56/A163/X157107/25/201810008708/02/201811008105/26/201811008008/03/2018100076
Arlington Municipal Airport C61107/23/201809007806/21/201812007704/24/201812007708/22/2018110076
Dallas North No.2 C63/C679107/26/201810009006/21/201811008505/26/201811008305/06/2018120081
Rockwall Heath C69105/06/201811008107/26/201811007904/28/201811007906/21/2018120078
Grapevine Fairway C70/A301/X182107/25/201811009205/26/201811008908/02/201811008307/26/2018120082
Kaufman C71/A304/X071108/20/201811007704/28/201811007004/24/201810006707/28/2018110065
Granbury C73/C681108/21/201812008007/24/201810007808/22/201812007408/02/2018120071
Eagle Mountain Lake C75 107/25/201812009505/17/201811009208/03/201810008408/02/2018120084
Parker County C76108/22/201812009108/02/201814007808/03/201810007505/17/2018110075
Cleburne Airport C77/C682108/21/201812008807/24/201810008507/23/201811008308/01/2018110081
Dallas Hinton St. C401/C60/AH161 306/21/201811008307/26/201811008104/24/201811008107/25/2018110080
Dallas Executive Airport C402104/24/201811008106/21/201811007808/21/201811007704/28/2018110075
Greenville C1006/A198107/27/201811008707/26/201811007807/21/201811007405/07/2018100073
Pilot Point C1032108/23/201810008008/02/201810007607/25/201812007507/28/2018110074
Italy C1044/A323108/21/201812007605/16/201812007205/07/201810007107/23/2018110069
Corsicana Airport C1051108/20/201813007304/28/201810007204/27/201812006808/21/2018110067
Tyler-Longview-Marshall
Longview C19/A127/C644207/28/201810006907/23/201809006908/23/201813006804/29/2018090068
Tyler Airport Relocated C82107/28/201812007404/28/201810007308/03/201812006908/02/2018110069
Karnack C85/AFHP303107/26/201809006507/27/201809006408/24/201810006107/21/2018100061
El Paso-Juarez
El Paso UTEP C12/A125/X151/G125207/29/201811009108/04/201811008606/04/201811008207/25/2018090076
Ascarate Park SE C37/A332/A172/X159106/04/201811008208/04/201810008107/29/201810007507/25/2018100075
Chamizal C41/AH126 108/04/201810008707/29/201811008606/04/201811008307/25/2018100078
Socorro Hueco C49/F312107/25/201811007508/13/201811007308/04/201810007106/04/2018120070
Skyline Park C72108/04/201811008407/25/201809008307/29/201811007906/04/2018110077
BRAVO Big Bend C67/C316/C656/C6913 N04/21/201812006908/02/201810006608/03/201812006508/01/2018110065
Ivanhoe C414/F514108/04/201810008707/25/201810008208/13/201811007406/04/2018110074
Waco
Waco Mazanec C1037105/07/201811006908/03/201810006804/28/201811006807/31/2018120067
Temple Georgia C1045105/07/201811007504/28/201809007108/02/201809007008/03/2018100069
Killeen Skylark Field C1047105/07/201811008108/02/201811007504/28/201810007508/03/2018100072
Beaumont-Port Arthur
Beaumont-Downtown C2/A112/C2002 207/27/201810008304/28/201811007504/25/201810007108/03/2018100068
West Orange C9/A141207/27/201810007704/25/201810007507/28/201809007305/16/2018110073
Port Arthur West C28/A128/A228107/27/201809008207/26/201809007508/23/201811007105/17/2018090070
Hamshire C64/C654105/17/201810007704/25/201809007208/23/201810007107/26/2018130069
SETRPC Port Arthur C6281 N07/27/201809008007/26/201810007805/17/201808007705/15/2018090071
SETRPC 40 Sabine Pass C640/C1654104/25/201811007607/26/201810007407/27/201808007104/28/2018110071
SETRPC Mauriceville 42 C642/C311/C6651 N04/28/201811007704/25/201811007705/16/201812007205/08/2018110072
SETRPC 43 Jefferson Co Airport C643107/27/201810008707/26/201808007504/28/201811007305/15/2018090072
Nederland High School C1035 107/27/201810007604/28/201812007304/25/201810006905/15/2018100067
Austin
Austin Northwest C3/A322208/02/201810007507/25/201811007407/31/201812007205/07/2018100072
Audubon C38108/02/201809007408/03/201810007005/07/201811007004/28/2018110070
Fayette County C6012 N08/03/201811007508/02/201811007004/28/201811006908/01/2018110067
Dripping Springs School C6141 N08/02/201811007707/25/201811007105/07/201811007107/31/2018120069
CAPCOG McKinney Roughs C6841 N07/31/201813006708/02/201811006608/03/201812006508/01/2018110060
CAPCOG Lake Georgetown C6901 N05/07/201810007708/02/201810007304/28/201810007308/03/2018100069
Gorzycki Middle School C16031 N08/02/201812008207/31/201813008007/25/201809007408/01/2018100073
Lockhart C16041 N05/06/201809006804/18/201813006708/02/201810006608/01/2018100066
St. Edwards University C16051 N08/02/201809007007/31/201812007008/01/201811006605/07/2018100066
CAPCOG San Marcos Staples Road C16751 N08/01/201811008408/02/201810008207/31/201811007607/26/2018100074
CAPCOG Hutto College Street C66021 N05/07/201810007105/16/201811007005/06/201810006804/28/2018100068
Houston-Galveston-Brazoria
Houston East C1/G316207/27/201812009408/23/201810008605/07/201811008404/28/2018100082
Houston Aldine C8/AF108/X150 207/27/2018110010908/24/201810009105/07/201810008804/28/2018110088
Channelview C15/AH115 307/27/201810008705/07/201810008104/28/201812008109/18/2018110079
Northwest Harris Co. C26/A110/X154207/27/201812009804/28/201811008308/23/201811008108/25/2018100077
Hou.DeerPrk2 C35/235/1001/AFH139FP239107/27/201810009109/18/201809008909/17/201811008807/26/2018100085
Seabrook Friendship Park C45107/27/201810008809/17/201811008604/24/201812008407/26/2018090082
Houston Bayland Park C53/A146 108/23/201812008204/28/201810007905/07/201811007807/26/2018090077
Conroe Relocated C78/A321108/24/201812008805/15/201810008507/28/201816008205/14/2018110075
Manvel Croix Park C84107/26/201810009208/02/201810007804/24/201811007707/25/2018100071
Clinton C403/C304/AH113 308/23/201811009905/07/201811007304/28/201810007307/26/2018100068
Houston North Wayside C405107/27/201811009004/28/201810008205/07/201810007905/17/2018110066
Houston Monroe C406107/26/201810008207/27/201810007404/24/201812006908/23/2018110068
Lang C408207/27/2018110010008/23/201811009004/28/201810008507/26/2018090074
Houston Croquet C409207/26/201811008407/24/201812007308/02/201809007007/25/2018100070
Houston Westhollow C410108/23/201810007704/28/201810007708/03/201809007608/02/2018090069
Park Place C416108/23/201811009007/27/201810008607/26/201809007905/07/2018110077
Baytown Wetlands Center C5521 N05/07/201811006204/24/201812005604/28/201812005404/25/2018090054
Crosby Library C5531 N08/24/201810008704/28/201811008604/25/201809008507/28/2018100082
La Porte Sylvan Beach C5561 N07/27/201810004708/02/201809004605/10/201809004305/09/2018130043
Tom Bass C5581 N07/26/201811007708/02/201811005807/25/201810005605/28/2018110055
Katy Park C5591 N08/03/201810006704/28/201811006007/26/201811005907/27/2018110057
Atascocita C5601 N07/27/201811008907/28/201811008505/07/201811008504/25/2018100077
Meyer Park C5611 N07/27/201812006304/28/201811005908/24/201811005008/23/2018120050
Bunker Hill Village C5621 N04/28/201810006607/27/201810006507/26/201809006308/23/2018120062
Huffman Wolf Road C5631 N08/24/201810004904/25/201810004807/28/201809004305/17/2018110043
HRM-3 Haden Road C603/A114 1 N07/27/201810009108/23/201810008205/07/201810007904/28/2018100078
Wallisville Road C617 1 N05/07/201811008808/24/201810008705/17/201810008207/27/2018100081
Danciger C618 1 N08/02/201809007208/01/201810006304/24/201809006304/19/2018110063
Texas City 34th St. C620 1 N08/01/201810009604/24/201811008807/27/201810008709/17/2018110078
UH Moody Tower C6951 N08/23/2018110010007/27/201810009305/07/201810008407/26/2018090083
UH WG Jones Forest C6981 N08/24/201812009007/28/201812008505/15/201812007707/27/2018120076
UH West Liberty C6991 N04/25/201809008008/24/201810007905/15/201810007204/28/2018110071
Lynchburg Ferry C1015/A165 107/27/201810008605/07/201811008309/18/201811008009/16/2018100074
Lake Jackson C1016 108/01/201813007708/02/201809007004/24/201810006907/26/2018100067
Baytown Garth C1017105/07/201811008805/17/201810008508/24/201810008407/27/2018100081
Galveston 99th St. C1034/A320/X183107/26/2018110010705/07/201811008304/24/201812008304/27/2018120076
UH Smith Point C16061 N09/18/201810009309/17/201810008407/26/201810007904/24/2018100079
Oyster Creek C1607 1 N08/01/201811009404/24/201811007008/02/201809006807/26/2018100068
San Antonio
San Antonio Northwest C23208/02/201811008305/07/201810007507/27/201809007304/23/2018120073
Camp Bullis C58 108/02/201811008305/07/201809008304/23/201812007707/26/2018100073
Calaveras Lake C59108/01/201811007908/02/201811007305/07/201811007105/06/2018110071
Elm Creek Elementary C5011 N08/02/201810007908/01/201811007607/24/201810007507/26/2018110071
Fair Oaks Ranch C5021 N05/07/201811007908/02/201811007704/28/201810007208/03/2018100071
Bulverde Elementary C5031 N08/02/201811007805/07/201811007807/26/201810007004/28/2018100070
New Braunfels Airport C5041 N08/01/201810007008/02/201810006905/07/201810006704/28/2018100064
City of Garden Ridge C5051 N08/02/201811008007/23/201811007605/07/201810007505/16/2018110073
Seguin Outdoor Learning Center C5061 N08/02/201810006908/01/201810006704/28/201810006505/07/2018100063
Heritage Middle School C6221 N08/01/201811007505/06/201811007308/02/201812007005/07/2018120068
CPS Pecan Valley C6781 N08/02/201810007608/01/201810007605/06/201810007105/07/2018100069
Government Canyon C16101 N08/02/201811008007/27/201810007708/03/201810007307/26/2018110071
Corpus Christi-Victoria
Corpus Christi West C4208/02/201810006604/27/201812006308/01/201811006204/28/2018120061
Corpus Christi Tuloso C21104/25/201808006604/27/201812006105/06/201811006004/28/2018110060
Victoria C87108/01/201811007408/02/201811007108/03/201808006607/26/2018100066
Holly Road C6601 N08/02/201810006808/01/201811006504/27/201813006404/28/2018120062
Violet C6641 N08/02/201810006308/01/201811006205/06/201810005805/07/2018090055
Ingleside C6851 N04/27/201812006904/28/201811006805/06/201811006308/02/2018100061
Lower Rio Grande Valley
Mission C43/AP143105/21/201809006508/02/201810006205/07/201810006104/23/2018120059
Brownsville C80/AGP180101/03/201810002501/02/201815002101/01/2018180020No Data
Harlingen Teege C1023104/25/201808006404/23/201813006004/28/201810005904/27/2018120059
Laredo
Laredo Vidaurri C44/AFGP144/P244108/02/201812006608/01/201812006205/07/201810005908/03/2018090058
POC (Parameter Occurrence Code): a code used to correctly separate data from multiple instruments at one site.
 N - Data from this instrument does not meet EPA quality assurance criteria and cannot be used for regulatory purposes.

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 Not Defined
401 - 500 Not Defined 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 TCEQ 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 TCEQ 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.

Following EPA reporting guidelines, negative values may be displayed in our hourly criteria air quality data, down to the negative of the EPA listed Method Detection Limit (MDL) for the particular instrument that made the measurements. The reported concentrations can be negative due to zero drift in the electronic instrument output, data logger channel, or calibration adjustments to the data. Prior to 1/1/2013, slightly negative values were automatically set to zero.