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Four Highest Eight-Hour Ozone Concentrations in 2026
as of February 25

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 2026 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 201/29/202615005402/17/202612004902/24/202608004801/26/2026100044
Keller C17201/29/202615005202/17/202612005102/24/202610004702/12/2026120047
Frisco C31/C680101/29/202614005802/24/202611005301/28/202610005302/17/2026120049
Denton Airport South C56/A163/X157101/28/202611006001/29/202614005702/17/202612005302/24/2026100050
Arlington Municipal Airport C61101/29/202616005302/24/202611005202/17/202612005102/09/2026120047
Dallas North No.2 C63/C679101/29/202614005502/24/202611005302/17/202612004802/09/2026140048
Rockwall Heath C69102/24/202612005101/29/202616005102/09/202612004602/12/2026120045
Grapevine Fairway C70/A301/X182101/29/202614005402/24/202610004901/28/202612004802/17/2026110047
Kaufman C71/A304/X071102/24/202611005701/29/202615005402/08/202611005202/09/2026110050
Granbury C73/C681101/29/202613004902/24/202609004702/17/202613004702/16/2026130046
Eagle Mountain Lake C75 101/29/202614005701/28/202612005502/17/202613005302/24/2026110051
Parker County C76101/29/202614005201/28/202612005102/24/202609004602/12/2026100046
Cleburne Airport C77/C682102/17/202612005101/29/202612005002/12/202611004902/24/2026100048
Dallas Executive Airport C402102/24/202612005601/29/202615005402/09/202612005102/17/2026110049
Greenville C1006/A198101/29/202614005702/24/202612005501/28/202610005302/19/2026110045
Pilot Point C1032101/28/202611006401/29/202614006002/24/202611005302/17/2026130052
Italy101/07/202611004401/18/202610003901/16/202612003901/01/2026110039
Corsicana Airport C1051102/24/202610005402/12/202612005201/29/202610005202/09/2026110050
Tyler-Longview-Marshall
Longview C19/A127/C644201/29/202619005702/12/202612005102/19/202612004802/08/2026090048
Tyler Airport Relocated C82102/24/202611005701/29/202613005602/17/202613005302/19/2026120050
Karnack C85/AFHP303102/24/202613006602/13/202612005001/29/202610005002/08/2026100048
El Paso-Juarez
Ascarate Park SE C37/A332/A172/X159102/20/202612004602/22/202610004502/21/202609004502/04/2026100042
Chamizal C41/AH126 102/21/202608004702/20/202611004501/30/202610004402/19/2026100043
Socorro Hueco C49/F312102/05/202610004602/22/202609004402/21/202609004402/06/2026100044
Skyline Park C72102/05/202610004802/20/202614004502/18/202613004502/04/2026100045
Ivanhoe C414/F514102/21/202610004302/20/202610004302/22/202609004102/19/2026090041
Ojo De Agua C1021/FG121/FG221102/21/202612004402/04/202609004402/22/202610004302/20/2026110043
Waco
Waco Mazanec C1037102/12/202613005602/24/202611005302/07/202612005102/17/2026110049
Temple Georgia C1045102/24/202610005302/07/202611005202/17/202611005102/12/2026110051
Killeen Skylark Field C1047102/24/202610005502/16/202612005302/07/202612005202/09/2026110050
Beaumont-Port Arthur
Beaumont-Downtown C2/A112/C2002 202/08/202609005202/24/202610005102/12/202613004701/29/2026100047
West Orange C9/A141202/24/202610005402/08/202610005302/10/202610004901/29/2026100049
Port Arthur West C28/A128/A228102/08/202609005402/24/202609005302/12/202613005302/10/2026080049
Hamshire C64/C654102/24/202610005502/12/202613005201/29/202610005001/19/2026110050
SETRPC Port Arthur C6281 N02/08/202610005301/30/202609005101/29/202610005102/12/2026130050
SETRPC 40 Sabine Pass C640/C1654102/24/202610006102/10/202609005802/08/202610005701/29/2026090057
SETRPC Mauriceville 42 C642/C311/C6651 N02/08/202610005901/29/202610005201/19/202611005202/10/2026100051
SETRPC 43 Jefferson Co Airport C643102/24/202610005202/08/202609005202/12/202613004801/30/2026090048
Nederland 17th Street C1035102/08/202610005402/12/202613005101/30/202609004901/29/2026100049
Austin
Austin North Hills Drive C3/A322202/24/202611005102/16/202612005102/07/202611005102/17/2026090049
Audubon C38102/07/202612005202/24/202610005102/09/202611004702/16/2026110046
CAPCOG Lake Georgetown C6901 N02/24/2026110051No DataNo DataNo Data
St. Edwards University C16051 N02/22/202612004502/21/202612004302/23/202610004202/24/2026100041
CAPCOG Round Rock Brushy Creek W C16201 N02/24/2026110046No DataNo DataNo Data
CAPCOG Lake Kyle Park C16301 N01/19/202611004001/18/202610003701/17/202611003501/26/2026100034
Houston-Galveston-Brazoria
Houston East C1/G316202/24/202610005102/12/202612004802/07/202611004801/29/2026090045
Houston Aldine C8/AF108/X150 202/12/202612005602/24/202610005402/07/202610005401/29/2026100049
Channelview C15/AH115 302/21/202614005102/22/202609004902/23/202610004802/12/2026120048
Northwest Harris Co. C26/A110/X154202/07/202611006102/24/202610005401/29/202610005102/12/2026110050
Hou.DeerPrk2 C35/235/1001/AFH139/FP239102/12/202611006102/24/202609005502/07/202611005501/29/2026090050
Seabrook Friendship Park C45102/24/202609005202/12/202610005202/07/202611004702/06/2026110045
Houston Bayland Park C53/A146 102/07/202612005702/12/202612005502/24/202609005102/21/2026120048
Conroe Relocated C78/A321102/07/202612005502/24/202611005301/29/202610004801/20/2026110048
Manvel Croix Park C84102/07/202612005602/12/202611005402/24/202610005202/06/2026110051
Clinton C403/C304/AH113 302/24/202610004302/12/202611004302/07/202611004302/21/2026130041
Houston North Wayside C405/C1033102/07/202611004702/12/202611004502/24/202610004401/04/2026100040
Houston Monroe C406102/12/202611005102/07/202611005102/24/202610005001/29/2026100045
Lang C408202/07/202611005502/12/202612005202/24/202610005101/29/2026100047
Houston Croquet C409202/07/202611005802/12/202611005602/24/202609005202/06/2026110050
Houston Westhollow C410/C3003102/07/202612006102/12/202611005502/24/202610005202/21/2026120049
Park Place C416102/12/202612005102/07/202611005002/24/202610004901/29/2026100046
Houston Harvard Street C417102/12/202612005502/07/202612005502/24/202610005201/29/2026100048
Sheldon C5511 N01/30/202601004301/17/202612004101/01/202611004101/16/2026220040
Baytown Wetlands Center C5521 N01/19/202612004701/20/202610004401/01/202609004301/17/2026100042
Crosby Library C5531 N02/07/202611004701/30/202602004601/29/202610004602/12/2026130045
West Houston C5541 N02/07/202612006302/24/202610005302/12/202612005302/21/2026120048
La Porte Sylvan Beach C5561 N02/24/202610005102/12/202613004902/07/202613004802/22/2026090043
Tom Bass C5581 N02/07/202612006002/24/202610005702/12/202612005701/29/2026100051
Katy Park C5591 N02/07/202613005701/29/202610004201/01/202610004102/06/2026100040
Atascocita C5601 N02/07/202613004902/12/202612004301/29/202609004301/20/2026100041
Meyer Park C5611 N02/07/202611005402/24/202610005202/12/202611004901/29/2026110048
Bunker Hill Village C5621 N02/07/202612005802/24/202610005202/12/202612005202/21/2026120046
Huffman Wolf Road C5631 N02/24/202610005701/29/202611005001/30/202601004801/20/2026100047
HRM-3 Haden Road C603/A114 1 N02/12/202612005102/07/202611005101/29/202609004702/08/2026110046
Wallisville Road C617 1 N02/12/202611005802/07/202611005201/29/202610005002/08/2026110049
Texas City 34th St. C620 1 N02/07/202611005602/12/202612005301/19/202610005302/06/2026100051
Lynchburg Ferry C1015/A165 102/24/202609005702/12/202612004802/10/202610004602/07/2026100046
Lake Jackson C1016 102/07/202612006902/06/202611005402/24/202609005202/21/2026130050
Baytown Garth C1017102/12/202611005802/24/202610005302/07/202612004901/29/2026100048
Galveston 99th St. C1034/A320/X183102/24/202609005502/07/202611005502/06/202613005301/29/2026080053
Oyster Creek C1607 1 N02/07/202611006802/06/202612005402/12/202610005302/08/2026100051
San Antonio
San Antonio Northwest C23202/07/202611005802/16/202611005001/28/202611004902/24/2026100048
Camp Bullis C58 102/07/202610005802/24/202611005102/16/202611005102/06/2026100050
Calaveras Lake C59102/07/202611005402/06/202610004902/23/202611004802/19/2026120048
Elm Creek Elementary C5011 N02/24/202610004702/23/202611004602/22/202610004402/21/2026110043
Fair Oaks Ranch C5021 N02/16/202612004202/24/202610004002/23/202611003802/17/2026110038
Bulverde Elementary C5031 N02/24/202610005302/23/202610004902/22/202611004602/21/2026120046
New Braunfels Airport C5041 N02/24/202611005102/23/202610004602/22/202611004502/21/2026120043
AACOG City of Garden Ridge C505 1 N02/24/202611005202/23/202611004802/22/202611004802/21/2026120046
Seguin Outdoor Learning Center C5061 N02/24/202610005202/23/202611004902/22/202611004502/21/2026120043
Heritage Middle School C6221 N02/07/202611006002/06/202611005302/16/202612004902/23/2026100047
CPS Pecan Valley C6781 N02/23/202610003702/22/202610003502/19/202613003402/16/2026110034
Corpus Christi-Victoria
Corpus Christi West C4202/07/202611005202/23/202611005002/21/202613004902/06/2026130049
Corpus Christi Tuloso C21102/07/202611005302/21/202613005101/30/202609004902/24/2026090048
Victoria C87102/07/202611005902/06/202613005802/21/202612005401/30/2026090054
Lower Rio Grande Valley
Mission C43/AP143102/20/202610005702/19/202611005402/06/202611005402/16/2026100050
Harlingen Teege C1023102/07/202611004901/30/202610004802/16/202610004701/19/2026100047
Laredo
Laredo College C441 N02/16/202611005501/06/202611005302/20/202611005202/15/2026110052
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.