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Four Highest Eight-Hour Ozone Concentrations in 2018
as of July 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 205/17/201811008304/24/201812007606/21/201812007505/26/2018110072
Keller C17205/17/201811008504/24/201812007704/28/201811007506/21/2018130074
Frisco C31/C680105/26/201811008105/07/201812008106/21/201813007604/28/2018120075
Midlothian OFW C52/A137104/24/201812007305/16/201812006805/07/201811006804/28/2018100066
Denton Airport South C56/A163/X157105/26/201811008005/29/201810007206/05/201810007104/28/2018110071
Arlington Municipal Airport C61106/21/201812007704/24/201812007705/26/201810007405/17/2018110069
Dallas North No.2 C63/C679106/21/201811008505/26/201811008305/06/201812008104/28/2018120081
Rockwall Heath C69105/06/201811008104/28/201811007906/21/201812007805/07/2018110076
Grapevine Fairway C70/A301/X182105/26/201811008905/07/201811007404/24/201811007405/17/2018110073
Kaufman C71/A304/X071104/28/201811007004/24/201810006705/07/201810006504/27/2018110065
Granbury C73/C681104/24/201811006807/07/201810006405/07/201811006405/06/2018100064
Eagle Mountain Lake C75 105/17/201811009204/24/201811007406/21/201811007307/09/2018100070
Parker County C76105/17/201811007504/24/201812007204/28/201811006305/07/2018110062
Cleburne Airport C77/C682105/16/201812008104/24/201811007106/03/201811006805/07/2018120068
Dallas Hinton St. C401/C60/AH161 306/21/201811008304/24/201811008105/06/201811007904/28/2018110076
Dallas Executive Airport C402104/24/201811008106/21/201811007804/28/201811007505/06/2018110073
Greenville C1006/A198105/07/201810007304/24/201810006406/21/201811006305/08/2018110063
Pilot Point C1032105/29/201811007405/07/201811007205/18/201810007105/08/2018110071
Italy C1044/A323105/16/201812007205/07/201810007104/28/201810006904/27/2018110069
Corsicana Airport C1051104/28/201810007204/27/201812006805/08/201811006605/07/2018100064
Tyler-Longview-Marshall
Longview C19/A127/C644204/29/201809006805/29/201811006604/28/201810006604/17/2018120064
Tyler Airport Relocated C82104/28/201810007304/12/201812006504/24/201810006405/29/2018090062
Karnack C85/AFHP303105/08/201810006103/15/201810006005/07/201811005905/16/2018100058
El Paso-Juarez
El Paso UTEP C12/A125/X151206/04/201811008206/21/201810007206/25/201811006905/22/2018100068
Ascarate Park SE C37/A332/A172/X159106/04/201811008206/21/201811007006/26/201810006505/22/2018100065
Chamizal C41/AH126 106/04/201811008306/21/201811007305/22/201810007005/19/2018110068
Socorro Hueco C49/F312106/04/201812007005/19/201810006205/09/201811006205/22/2018100061
Skyline Park C72106/04/201811007706/21/201811007606/27/201810007506/26/2018100072
BRAVO Big Bend C67/C316/C656/C6913 N04/21/201812006905/19/201810006505/01/201811006504/17/2018150063
Ivanhoe C414106/04/201811007405/22/201810006605/18/201814006605/19/2018100065
Waco
Waco Mazanec C1037105/07/201811006904/28/201811006804/29/201814006404/24/2018110064
Temple Georgia C1045105/07/201811007504/28/201809007105/06/201810006504/24/2018100064
Killeen Skylark Field C1047105/07/201811008104/28/201810007505/08/201811007105/17/2018110067
Beaumont-Port Arthur
Beaumont-Downtown C2/A112/C2002 204/28/201811007504/25/201810007105/16/201811006805/15/2018100064
West Orange C9/A141204/25/201810007505/16/201811007305/08/201810007304/28/2018100072
Port Arthur West C28/A128/A228105/17/201809007005/15/201809006904/28/201811006904/25/2018100067
Hamshire C64/C654105/17/201810007704/25/201809007204/28/201810006605/16/2018100065
SETRPC Port Arthur C6281 N05/17/201808007705/15/201809007104/28/201811006805/07/2018100067
SETRPC 40 Sabine Pass C640/C1654104/25/201811007604/28/201811007105/28/201811006805/08/2018110067
SETRPC Mauriceville 42 C642/C311/C6651 N04/28/201811007704/25/201811007705/16/201812007205/08/2018110072
SETRPC 43 Jefferson Co Airport C643104/28/201811007305/15/201809007204/25/201810007105/17/2018090067
Nederland High School C1035 104/28/201812007304/25/201810006905/15/201810006705/08/2018110066
Austin
Austin Northwest C3/A322205/07/201810007204/28/201810007005/06/201811006604/24/2018110065
Audubon C38105/07/201811007004/28/201811007004/24/201810006705/06/2018110064
Fayette County C6012 N04/28/201811006905/07/201810006205/06/201809006204/29/2018090062
Dripping Springs School C6141 N05/07/201811007104/24/201812006904/28/201810006804/18/2018120065
CAPCOG McKinney Roughs C6841 N04/18/201813005404/23/201811005305/06/201810005205/29/2018110051
CAPCOG Lake Georgetown C6901 N05/07/201810007704/28/201810007304/24/201810006905/29/2018100067
Gorzycki Middle School C16031 N05/07/201811007105/06/201812006605/29/201810006305/26/2018120060
Lockhart C16041 N05/06/201809006804/18/201813006704/23/201810006504/27/2018100064
St. Edwards University C16051 N05/07/201810006605/06/201811006404/18/201812006404/28/2018100063
CAPCOG San Marcos Staples Road C16751 N04/28/201810006905/07/201810006805/06/201810006604/24/2018110066
CAPCOG Hutto College Street C66021 N05/07/201810007105/16/201811007005/06/201810006804/28/2018100068
Houston-Galveston-Brazoria
Houston East C1/G316205/07/201811008404/28/201810008205/17/201811007704/25/2018100073
Houston Aldine C8/AF108/X150 205/07/201810008804/28/201811008804/25/201810007805/17/2018120075
Channelview C15/AH115 305/07/201810008104/28/201812008105/15/201810007305/17/2018100072
Northwest Harris Co. C26/A110/X154204/28/201811008304/29/201810007205/15/201810006804/25/2018090067
Hou.DeerPrk2 C35/235/1001/AFH139FP239105/07/201810008404/24/201812007604/28/201810007104/25/2018090069
Seabrook Friendship Park C45104/24/201812008405/07/201811006904/25/201808006604/28/2018120064
Houston Bayland Park C53/A146 104/28/201810007905/07/201811007804/25/201810007304/24/2018100070
Conroe Relocated C78/A321105/15/201810008505/14/201811007505/09/201811007506/08/2018110073
Manvel Croix Park C84104/24/201811007705/28/201810006905/06/201810006804/28/2018100067
Clinton C403/C304/AH113 305/07/201811007304/28/201810007304/24/201810006604/29/2018090062
Houston North Wayside C405104/28/201810008205/07/201810007905/17/201811006604/29/2018100064
Houston Monroe C406104/24/201812006905/07/201811006605/28/201811006304/25/2018090062
Lang C408204/28/201810008505/07/201811007304/25/201809007204/29/2018100069
Houston Croquet C409204/28/201810006704/25/201809006704/24/201810006705/07/2018110065
Houston Westhollow C410104/28/201810007705/07/201811006904/25/201809006904/24/2018100067
Park Place C416105/07/201811007704/28/201810007304/24/201812007204/25/2018090070
Baytown Wetlands Center C5521 N05/07/201811006204/24/201812005604/28/201812005404/25/2018090054
Crosby Library C5531 N04/28/201811008604/25/201809008505/15/201810008205/07/2018110082
La Porte Sylvan Beach C5561 N05/10/201809004305/09/201813004304/16/201813004205/16/2018100040
Tom Bass C5581 N05/28/201811005505/07/201811005504/29/201810005504/28/2018120054
Katy Park C5591 N04/28/201811006004/25/201809005404/24/201810005305/07/2018110051
Atascocita C5601 N05/07/201811008504/25/201810007705/15/201810007605/17/2018110072
Meyer Park C5611 N04/28/201811005905/15/201810004605/07/201811004604/29/2018100046
Bunker Hill Village C5621 N04/28/201810006605/07/201811005904/25/201810005604/29/2018100054
Huffman Wolf Road C5631 N04/25/201810004805/17/201811004303/29/201811003604/16/2018110035
HRM-3 Haden Road C603/A114 1 N05/07/201810007904/28/201810007805/17/201810007004/25/2018100068
Wallisville Road C617 1 N05/07/201811008805/17/201810008205/15/201809008104/25/2018090078
Danciger C618 1 N04/24/201809006304/19/201811006303/14/201811006204/28/2018100060
Texas City 34th St. C620 1 N04/24/201811008805/07/201810007404/27/201812007104/28/2018110070
UH Moody Tower C6951 N05/07/201810008404/28/201810007804/25/201810007404/24/2018110072
UH WG Jones Forest C6981 N05/15/201812007706/08/201810007604/28/201812007505/08/2018110074
UH West Liberty C6991 N04/25/201809008005/15/201810007204/28/201811007105/08/2018100068
Lynchburg Ferry C1015/A165 105/07/201811008304/28/201811007105/15/201810007005/17/2018090067
Lake Jackson C1016 104/24/201810006904/27/201811006704/28/201810006605/06/2018110063
Baytown Garth C1017105/07/201811008805/17/201810008505/15/201809008104/25/2018090081
Galveston 99th St. C1034/A320/X183105/07/201811008304/24/201812008304/27/201812007604/28/2018110072
Oyster Creek C1607 1 N04/24/201811007004/28/201811006604/27/201811006605/05/2018150064
San Antonio
San Antonio Northwest C23205/07/201810007504/23/201812007304/28/201810006904/24/2018110067
Camp Bullis C58 105/07/201809008304/23/201812007704/24/201809007304/28/2018100072
Calaveras Lake C59105/07/201811007105/06/201811007104/28/201810006804/24/2018110066
Elm Creek Elementary C5011 N05/06/201811006705/07/201810006604/28/201810006504/23/2018110062
Fair Oaks Ranch C5021 N05/07/201811007904/28/201810007204/24/201811006904/23/2018130067
Bulverde Elementary C5031 N05/07/201811007804/28/201810007004/24/201811006904/23/2018120068
New Braunfels Airport C5041 N05/07/201810006704/28/201810006404/24/201811006305/06/2018100061
City of Garden Ridge C5051 N05/07/201810007505/16/201811007304/23/201812007104/28/2018100068
Seguin Outdoor Learning Center C5061 N04/28/201810006505/07/201810006305/06/201811006304/27/2018110061
Heritage Middle School C6221 N05/06/201811007305/07/201812006804/28/201811006504/24/2018120063
CPS Pecan Valley C6781 N05/06/201810007105/07/201810006905/16/201811006005/08/2018110054
Government Canyon C16101 N05/07/201810006704/24/201811006704/23/201811006604/28/2018090065
Corpus Christi-Victoria
Corpus Christi West C4204/27/201812006304/28/201812006104/25/201807006004/19/2018120059
Corpus Christi Tuloso C21104/25/201808006604/27/201812006105/06/201811006004/28/2018110060
Victoria C87105/06/201810006405/07/201810006205/09/201810005205/08/2018090051
Holly Road C6601 N04/27/201813006404/28/201812006204/19/201814006204/25/2018070060
Violet C6641 N05/06/201810005805/07/201809005504/29/201808005203/08/2018110051
Ingleside C6851 N04/27/201812006904/28/201811006805/06/201811006304/15/2018110059
Lower Rio Grande Valley
Mission C43/AP143105/21/201809006505/07/201810006004/23/201812005903/14/2018100059
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/P244104/22/201811005704/28/201810005504/27/201811005505/21/2018130054
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.