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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
6:11 pm CDT
Dallas-Fort Worth
Corsicana Airport C1051167666465
Rockwall Heath C69163626764
Kaufman C71/A304/X071163697167
Dallas Executive Airport C402170777975
Parker County C76167757873
Granbury C73/C681165817975
Grapevine Fairway C70/A301/X182175788479
Dallas North No.2 C63/C679173728075
Pilot Point C1032185778181
Dallas Hinton St. C401/C60/AH161 374637972
Denton Airport South C56/A163/X157181787879
Ft. Worth Northwest C13/AH302 276808480
Midlothian OFW C52/A13716463 *  
Frisco C31/C680181738278
Italy C1044/A323164667066
Cleburne Airport C77/C682175827577
Arlington Municipal Airport C61171777474
Keller C17274728075
Greenville C1006/A198165656966
Eagle Mountain Lake C75 176778178
Longview C19/A127/C644264646765
Tyler Airport Relocated C82165717169
Karnack C85/AFHP303161656563
El Paso-Juarez
Ivanhoe C414/F514164646464
El Paso UTEP C12/A125/X151/G125273   
Socorro Hueco C49/F312171756670
Ojo De Agua C1021/FG121/FG221171797474
Skyline Park C72168726869
Chamizal C41/AH126 169686868
Ascarate Park SE C37/A332/A172/X159156686964
Waco Mazanec C1037167627668
Temple Georgia C1045167677670
Killeen Skylark Field C1047170697671
Beaumont-Port Arthur
SETRPC 43 Jefferson Co Airport C643166656665
Nederland 17th Street C103516465 *7066
SETRPC 40 Sabine Pass C640/C1654160626863
Hamshire C64/C654162626763
West Orange C9/A141261626863
Port Arthur West C28/A128/A228165606362
Beaumont-Downtown C2/A112/C2002 265616864
Audubon C38165667067
Austin North Hills Drive C3/A322266737471
Seabrook Friendship Park C45160597364
Houston Westhollow C410/C3003171737773
Hou.DeerPrk2 C35/235/1001/AFH139FP239174688375
Houston Harvard Street C417179787878
Houston North Wayside C405/C1033165627467
Houston Monroe C406168607868
Conroe Relocated C78/A321170737271
Houston East C1/G316276739079
Channelview C15/AH115 368638572
Lake Jackson C1016 169697370
Baytown Garth C1017171718375
Park Place C416178728578
Houston Croquet C409283728078
Houston Aldine C8/AF108/X150 275647872
Houston Bayland Park C53/A146 178848783
Clinton C403/C304/AH113 370768276
Northwest Harris Co. C26/A110/X154269747974
Manvel Croix Park C84177728277
Lang C408271718375
Galveston 99th St. C1034/A320/X183170738174
Lynchburg Ferry C1015/A165 165638270
San Antonio
Camp Bullis C58 178757676
Calaveras Lake C59166707169
San Antonio Northwest C23270767473
Corpus Christi-Victoria
Victoria C87161605960
Corpus Christi West C4265626463
Corpus Christi Tuloso C21164576562
Lower Rio Grande Valley
Mission C43/AP1431626351 **58
Harlingen Teege C1023156576057
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 (249 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.