Skip to main content

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
11:10 pm CDT
Dallas-Fort Worth
Corsicana Airport C1051167666164
Rockwall Heath C69163625359
Kaufman C71/A304/X071163696365
Dallas Executive Airport C4021707768 **71
Parker County C76167756468
Granbury C73/C681165816570
Grapevine Fairway C70/A301/X182175786873
Dallas North No.2 C63/C6791737265 **70
Pilot Point C1032185776575
Dallas Hinton St. C401/C60/AH161 374636366
Denton Airport South C56/A163/X157181787678
Ft. Worth Northwest C13/AH302 276807476
Midlothian OFW C52/A13716463 *  
Frisco C31/C680181736673
Italy C1044/A323164666364
Cleburne Airport C77/C682175826574
Arlington Municipal Airport C61171776671
Keller C17274726871
Greenville C1006/A198165655862
Eagle Mountain Lake C75 176777174
Longview C19/A127/C644264646564
Tyler Airport Relocated C82165716868
Karnack C85/AFHP303161656162
El Paso-Juarez
Ivanhoe C414/F514164645862
El Paso UTEP C12/A125/X151/G125273   
Socorro Hueco C49/F312171756470
Ojo De Agua C1021/FG121/FG221171796571
Skyline Park C72168726367
Chamizal C41/AH126 169686065
Ascarate Park SE C37/A332/A172/X159156685660
Waco Mazanec C1037167626564
Temple Georgia C1045167676265
Killeen Skylark Field C1047170696066
Beaumont-Port Arthur
SETRPC 43 Jefferson Co Airport C643166656264
Nederland 17th Street C103516465 *6865
SETRPC 40 Sabine Pass C640/C1654160626662
Hamshire C64/C654162626462
West Orange C9/A141261626462
Port Arthur West C28/A128/A228165606262
Beaumont-Downtown C2/A112/C2002 265616664
Audubon C38165666164
Austin North Hills Drive C3/A322266736768
Seabrook Friendship Park C45160597063
Houston Westhollow C410/C3003171736870
Hou.DeerPrk2 C35/235/1001/AFH139FP239174687873
Houston Harvard Street C417179787677
Houston North Wayside C405/C1033165626865
Houston Monroe C406168607266
Conroe Relocated C78/A321170736770
Houston East C1/G316276738477
Channelview C15/AH115 368637267
Lake Jackson C1016 169696668
Baytown Garth C1017171717873
Park Place C416178728076
Houston Croquet C409283727576
Houston Aldine C8/AF108/X150 275646668
Houston Bayland Park C53/A146 178847779
Clinton C403/C304/AH113 370767373
Northwest Harris Co. C26/A110/X154269747572
Manvel Croix Park C84177727775
Lang C408271717572
Galveston 99th St. C1034/A320/X183170737873
Lynchburg Ferry C1015/A165 165637066
San Antonio
Camp Bullis C58 178756572
Calaveras Lake C59166706366
San Antonio Northwest C23270766169
Corpus Christi-Victoria
Victoria C87161605458
Corpus Christi West C4265625761
Corpus Christi Tuloso C21164576160
Lower Rio Grande Valley
Mission C43/AP14316263  
Harlingen Teege C1023156575656
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 (119 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.