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Four Highest Eight-Hour Ozone Concentrations in 2017
as of March 28

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 2017 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 202/23/201712005703/03/201711004802/22/201711004702/01/2017110047
Keller C17202/23/201712005903/03/201711005302/22/201712005203/23/2017140050
Frisco C31/C680102/23/201711006002/22/201712005203/03/201711005103/21/2017110049
Midlothian OFW C52/A137102/23/201711006002/22/201712005603/03/201710005203/02/2017100049
Denton Airport South C56/A163/X157102/23/201712006302/22/201712005403/03/201711005303/18/2017110052
Arlington Municipal Airport C61102/23/201711005503/03/201711004702/22/201711004702/10/2017120045
Dallas North No.2 C63/C679102/23/201711006003/03/201711005202/22/201712005203/23/2017120048
Rockwall Heath C69102/23/201711005303/03/201711004902/22/201711004701/31/2017130047
Grapevine Fairway C70/A301/X182102/23/201712005602/10/201712004903/23/201712004703/03/2017110047
Kaufman C71/A304/X071102/23/201710005401/31/201712005103/03/201710005002/22/2017130050
Granbury C73/C681103/24/201712005203/15/201713005103/03/201711005102/23/2017170051
Eagle Mountain Lake C75 102/23/201713005603/24/201712005303/03/201711005302/22/2017120052
Parker County C76103/24/201711005103/03/201710005002/23/201719005002/22/2017100049
Cleburne Airport C77/C682102/23/201712006603/03/201711005702/22/201712005503/27/2017120053
Dallas Hinton St. C401/C60/AH161 302/23/201711005802/22/201711005003/23/201713004803/03/2017110048
Dallas Executive Airport C402103/03/201710004702/17/201712004503/23/201713004402/16/2017110043
Greenville C1006/A198102/23/201710005703/03/201710005503/23/201714005102/22/2017110051
Pilot Point C1032102/23/201712005803/21/201712004902/10/201711004903/23/2017110048
Italy C1044/A323102/23/201710005703/27/201712005203/03/201710005102/22/2017100051
Corsicana Airport C1051102/23/201711005503/23/201712005102/22/201711005102/18/2017120051
Tyler-Longview-Marshall
Longview C19/A127/C644202/23/201711006203/03/201711005301/31/201711005301/24/2017110050
Tyler Airport Relocated C82102/23/201714006703/23/201712005603/03/201711005501/31/2017120053
Karnack C85/AFHP303102/23/201711006003/03/201710005201/31/201711005002/17/2017110049
El Paso-Juarez
El Paso UTEP C12/A125/X151203/18/201711006103/08/201710005803/23/201715005603/19/2017100053
Ascarate Park SE C37/A332/A172/X159103/08/201710006203/18/201710005603/26/201713005503/19/2017100052
Chamizal C41/AH126 103/18/201710006203/08/201710005903/19/201710005803/26/2017120057
Socorro Hueco C49/F312103/08/201710005803/26/201712005203/18/201711005203/23/2017150051
Skyline Park C72103/26/201712005803/23/201715005603/18/201710005603/08/2017100056
BRAVO Big Bend C67/C316/C656/C6913 N03/26/201712006003/07/201717006003/23/201720005803/24/2017060056
Ivanhoe C414103/08/201710005403/26/201711005303/23/201715005303/18/2017100052
Waco
Waco Mazanec C1037102/23/201710005603/03/201711005102/22/201712005003/23/2017120049
Temple Georgia C1045102/23/201711006103/15/201711005802/22/201712005803/03/2017100055
Killeen Skylark Field C1047102/23/201710006202/22/201712005603/15/201711005503/03/2017110054
Beaumont-Port Arthur
Beaumont-Downtown C2/A112/C2002 202/23/201710005302/26/201711005102/16/201711005103/03/2017100050
West Orange C9/A141203/03/201711004902/16/201712004902/26/201712004802/23/2017100048
Port Arthur West C28/A128/A228103/03/201713005502/23/201710005302/22/201711005302/16/2017110052
Hamshire C64/C654102/16/201712005502/23/201709005302/26/201711005203/03/2017100051
SETRPC Port Arthur C6281 N01/30/201710005001/31/201709004701/24/201709004701/29/2017110045
SETRPC 40 Sabine Pass C640/C1654102/22/201712005902/23/201710005803/03/201712005702/16/2017130057
SETRPC Mauriceville 42 C642/C311/C6651 N01/30/201712004801/24/201711004601/29/201711004201/28/2017120041
SETRPC 43 Jefferson Co Airport C643103/03/201713005302/26/201712005202/23/201710005202/16/2017110052
Nederland High School C1035 103/03/201712005102/26/201713005102/23/201710005102/22/2017120051
Austin
Austin Northwest C3/A322202/23/201711005602/22/201711005503/02/201711005102/18/2017110051
Audubon C38102/23/201711006102/22/201713005903/02/201710005101/31/2017110051
Fayette County C6012 N03/03/201711005403/15/201711005303/01/201713005103/23/2017110050
Dripping Springs School C6141 N02/23/201711005803/02/201711005203/26/201711005003/15/2017120049
CAPCOG McKinney Roughs C6841 N03/25/201712005003/03/201711005003/02/201712004903/01/2017120049
CAPCOG Lake Georgetown C6901 N03/03/201711005403/15/201711005303/02/201710005303/01/2017120051
Gorzycki Middle School C16031 N02/23/201711005803/02/201711005003/03/201711004903/01/2017120047
Lockhart C16041 N03/01/201712005502/23/201711005502/22/201711005503/02/2017100051
St. Edwards University C16051 N02/22/201711004802/23/201711004603/02/201711004403/01/2017120043
CAPCOG San Marcos Staples Road C16751 N03/02/201710005003/25/201712004903/03/201711004903/23/2017110048
CAPCOG Hutto College Street C66021 N03/03/201711005003/02/201710005003/15/201711004903/01/2017110048
Houston-Galveston-Brazoria
Houston East C1/G316202/23/201710005202/22/201711005202/26/201710005103/22/2017100050
Houston Aldine C8/AF108/X150 202/22/201711005602/23/201709005403/22/201710005302/26/2017100052
Channelview C15/AH115 303/25/201712005402/24/201709004902/22/201711004902/26/2017110047
Northwest Harris Co. C26/A110/X154202/23/201710005203/23/201711004903/03/201710004902/26/2017110049
Hou.DeerPrk2 C35/235/1001/AFH139FP239102/22/201711005603/25/201711005302/26/201709004902/23/2017090049
Seabrook Friendship Park C45102/22/201712006203/03/201714005503/25/201710005302/23/2017100053
Houston Bayland Park C53/A146 102/22/201711005502/23/201710005203/03/201711004902/26/2017100049
Conroe Relocated C78/A321102/23/201710006503/22/201711006303/23/201710005903/26/2017100056
Manvel Croix Park C84102/22/201711006102/09/201712005302/23/201709005202/16/2017110052
Clinton C403/C304/AH113 302/26/201709004802/22/201713004803/03/201710004702/09/2017110046
Houston North Wayside C405102/26/201710004902/23/201710004703/23/201709004603/03/2017110046
Houston Monroe C406103/03/201711004102/26/201709004102/24/201709004102/23/2017100041
Lang C408202/23/201710004902/22/201710004902/26/201710004603/03/2017100044
Houston Croquet C409202/22/201710005502/23/201710005102/26/201710004903/03/2017110048
Houston Westhollow C410102/22/201711005302/23/201710004903/23/201710004803/03/2017110047
Park Place C416102/22/201711005203/25/201711004702/26/201709004602/23/2017090046
Sheldon C5511 N02/22/201711004103/25/201711003803/03/201711003802/26/2017100038
Baytown Wetlands Center C5521 N03/03/201713003902/22/201712003902/16/201713003902/26/2017100038
West Houston C5541 N01/08/201710003701/03/201710003701/14/201710003601/12/2017100035
La Porte Sylvan Beach C5561 N01/03/201709003503/03/201713003102/26/201711002802/23/2017100028
Mercer Arboretum C5571 N02/26/201710004102/23/201710004003/03/201709003802/22/2017110038
Tom Bass C5581 N02/09/201713004501/30/201711004101/31/201710004001/29/2017110038
Katy Park C5591 N03/03/201711004402/26/201710004302/22/201711004302/23/2017100042
Atascocita C5601 N03/03/201711004501/24/201709003801/29/201710003701/28/2017100037
Meyer Park C5611 N02/23/201710004203/03/201710004003/22/201710003902/26/2017100038
Bunker Hill Village C5621 N01/03/201710003401/08/201710003301/07/201709003101/02/2017090031
Huffman Wolf Road C5631 N03/15/2017210017703/16/2017000016502/22/201712006203/03/2017120061
Clear Brook High School C5701 N02/22/201711005402/16/201712005202/23/201709004903/25/2017110048
Clear Creek High School C5711 N02/22/201712005203/25/201711005001/30/201711004401/31/2017100043
HRM-3 Haden Road C603/A114 1 N02/22/201710005503/25/201711005202/26/201710005003/22/2017090049
Wallisville Road C617 1 N02/22/201712005703/25/201711005602/23/201710005602/26/2017100052
Danciger C618 1 N02/22/201711005502/16/201712005403/03/201711005102/25/2017120051
Texas City 34th St. C620 1 N02/22/201712006503/03/201713005702/26/201708005403/02/2017170053
UH Moody Tower C6951 N02/22/201712005802/23/201710005103/25/201711005002/26/2017100050
U of H-Sugarland C6961 N02/22/201712005702/09/201713005303/03/201711005202/16/2017130052
UH Coastal Center C6971 N02/22/201712005902/26/201711005102/23/201710005002/09/2017110048
UH WG Jones Forest C6981 N02/23/201710006303/22/201711005903/23/201711005603/26/2017100055
UH West Liberty C6991 N02/23/201710005303/03/201712005002/22/201712004902/26/2017110047
Lynchburg Ferry C1015/A165 102/22/201712004603/03/201715004402/26/201711004202/23/2017080042
Lake Jackson C1016 102/22/201711005402/16/201711005403/03/201712005302/26/2017080051
Baytown Garth C1017102/23/201710005702/22/201712005703/25/201711005602/26/2017110054
Galveston 99th St. C1034/A320/X183102/22/201713006902/23/201709005802/16/201715005803/03/2017160057
Oyster Creek C1607 1 N02/26/201708004902/22/201710004902/16/201712004903/03/2017110047
San Antonio
San Antonio Northwest C23202/23/201712005403/25/201711005103/26/201710004903/15/2017090049
Camp Bullis C58 101/31/201710005402/23/201713005303/02/201710005003/26/2017100049
Calaveras Lake C59102/23/201711005402/22/201711005201/31/201711005103/25/2017130050
Elm Creek Elementary C5011 N03/03/201712005103/02/201710005103/25/201711005003/26/2017100049
Fair Oaks Ranch C5021 N03/26/201710005003/02/201711005003/24/201713004903/15/2017100049
Bulverde Elementary C5031 N02/23/201711006103/15/201710005203/02/201711005203/26/2017110051
New Braunfels Airport C5041 N02/22/201710005503/25/201711005002/23/201709004703/02/2017100045
City of Garden Ridge C5051 N03/25/201713005703/02/201711005203/03/201711005002/24/2017110050
Seguin Outdoor Learning Center C5061 N02/23/201711006202/22/201712005903/25/201711004903/23/2017110045
Heritage Middle School C6221 N03/25/201712005602/23/201711005503/03/201712005103/02/2017100051
CPS Pecan Valley C6781 N02/22/201710004601/31/201710004603/03/201712004503/02/2017100045
Corpus Christi-Victoria
Corpus Christi West C4202/22/201710006402/25/201715006102/24/201711005602/21/2017100054
Corpus Christi Tuloso C21102/22/201711006001/31/201710005202/25/201712005102/24/2017110051
Victoria C87102/22/201711005302/24/201712005102/16/201711005003/25/2017110049
Holly Road C6601 N02/22/201711006802/25/201713006603/02/201713006303/03/2017180059
Violet C6641 N02/22/201710005601/31/201710004903/14/201712004603/02/2017100046
Ingleside C6851 N02/25/201713005403/15/201709005203/02/201712005202/22/2017130051
Lower Rio Grande Valley
Mission C43/AP143103/02/201713004802/25/201711004802/09/201712004603/25/2017100045
Brownsville C80/AGP180102/22/201711005402/24/201709005002/25/201711004902/23/2017090047
Harlingen Teege C1023102/22/201711005602/24/201711005103/02/201711004902/25/2017100049
Laredo
Laredo Vidaurri C44/AFGP144/P244103/25/201711005003/02/201713004303/24/201711004102/23/2017100041
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

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.