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Compliance with Eight-Hour Ozone Standard

In July 1997, the U. S. Environmental Protection Agency (EPA) announced a new National Ambient Air Quality Standard (NAAQS) for ground-level ozone. The EPA phased out and replaced the previous one-hour standard with an eight-hour standard to protect public health against longer exposure to this air pollutant. In March 2008, the EPA updated the eight-hour standard again. A community will meet the eight-hour standard when the three-year average of the annual fourth highest daily maximum eight-hour ozone concentration measured at each monitoring site is less than 71 parts per billion (ppb).

Highlighted rows show the monitor in each area that may ultimately be used to determine the area's compliance with the ozone standard. These highlighted monitors have measured an area's ozone concentrations over the past three years.

Below are the annual fourth highest daily maximum eight-hour average ozone concentrations from data collected beginning January 1, 2021, to date. Data is updated each hour. Data is given for each area that has ozone monitors.

Use the selection boxes below to customize this report. If you want to cut and paste data from this 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
AreaMonitoring SitePOCFourth Highest AverageCurrent
as of
0:10 am CDT
Dallas-Fort Worth
Corsicana Airport C1051167664057
Rockwall Heath C69163623553
Kaufman C71/A304/X071163694358
Dallas Executive Airport C402170774162
Parker County C76167754161
Granbury C73/C681165814162
Grapevine Fairway C70/A301/X182175783663
Dallas North No.2 C63/C679173723560
Pilot Point C1032185774167
Dallas Hinton St. C401/C60/AH161 374633356
Denton Airport South C56/A163/X157181784267
Ft. Worth Northwest C13/AH302 276804266
Midlothian OFW C52/A13716463 *  
Frisco C31/C680181733964
Italy C1044/A323164664157
Cleburne Airport C77/C682175824266
Arlington Municipal Airport C61171774062
Keller C17274723961
Greenville C1006/A198165653956
Eagle Mountain Lake C75 176774265
Longview C19/A127/C644264643855
Tyler Airport Relocated C82165714259
Karnack C85/AFHP303161653955
El Paso-Juarez
Ivanhoe C414/F514164643855
El Paso UTEP C12/A125/X151/G125273   
Socorro Hueco C49/F312171753961
Ojo De Agua C1021/FG121/FG221171793862
Skyline Park C72168724361
Chamizal C41/AH126 169684159
Ascarate Park SE C37/A332/A172/X159156683352
Waco Mazanec C1037167624257
Temple Georgia C1045167674359
Killeen Skylark Field C1047170694661
Beaumont-Port Arthur
SETRPC 43 Jefferson Co Airport C643166653455
Nederland 17th Street C103516465 *4056
SETRPC 40 Sabine Pass C640/C1654160623953
Hamshire C64/C654162624255
West Orange C9/A141261623853
Port Arthur West C28/A128/A2281656024 **49
Beaumont-Downtown C2/A112/C2002 265613955
Audubon C38165663655
Austin North Hills Drive C3/A322266734762
Seabrook Friendship Park C45160593852
Houston Westhollow C410/C3003171733459
Hou.DeerPrk2 C35/235/1001/AFH139FP239174683759
Houston Harvard Street C417179783664
Houston North Wayside C405/C1033165623353
Houston Monroe C406168603654
Conroe Relocated C78/A321170734462
Houston East C1/G316276733962
Channelview C15/AH115 368633555
Lake Jackson C1016 169694561
Baytown Garth C1017171714361
Park Place C416178723762
Houston Croquet C409283723864
Houston Aldine C8/AF108/X150 275643558
Houston Bayland Park C53/A146 178843967
Clinton C403/C304/AH113 370763460
Northwest Harris Co. C26/A110/X154269744061
Manvel Croix Park C84177724263
Lang C408271713659
Galveston 99th St. C1034/A320/X183170734261
Lynchburg Ferry C1015/A165 165633554
San Antonio
Camp Bullis C58 178754265
Calaveras Lake C59166704259
San Antonio Northwest C23270764262
Corpus Christi-Victoria
Victoria C87161604053
Corpus Christi West C4265624356
Corpus Christi Tuloso C21164574455
Lower Rio Grande Valley
Mission C43/AP14316263  
Harlingen Teege C1023156574653
Laredo College C44160 *   
* The value shown for this site does not represent an entire year's worth of data (274 days of valid data).
** The value shown for this site does not represent a complete set of data for 2023 (20 days of valid data).

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.