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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, 2019, 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
9:10 pm CDT
Dallas-Fort Worth
Corsicana Airport C1051162635459
Rockwall Heath C69164645260
Kaufman C71/A304/X071163655360
Dallas Executive Airport C402167675964
Parker County C76168685965
Granbury C73/C681166625862
Grapevine Fairway C70/A301/X182171775367
Dallas North No.2 C63/C679173695666
Pilot Point C1032173716168
Dallas Hinton St. C401/C60/AH161 365645561
Denton Airport South C56/A163/X157171716268
Ft. Worth Northwest C13/AH302 267755967
Midlothian OFW C52/A137163615860
Frisco C31/C680176705968
Italy C1044/A323159605558
Cleburne Airport C77/C682173676167
Arlington Municipal Airport C61164685863
Keller C17271715666
Greenville C1006/A198161615659
Eagle Mountain Lake C75 175766170
Longview C19/A127/C644267555458
Tyler Airport Relocated C82167605761
Karnack C85/AFHP303162555457
El Paso-Juarez
Ivanhoe C414/F514170685664
El Paso UTEP C12/A125/X151/G125275795971
Socorro Hueco C49/F312167745866
Ojo De Agua C1021/FG121/FG2211  64 ** 
Skyline Park C72172715766
Chamizal C41/AH126 173725466
Ascarate Park SE C37/A332/A172/X159164695261
Waco Mazanec C1037163635961
Temple Georgia C1045163646263
Killeen Skylark Field C1047167636364
Beaumont-Port Arthur
SETRPC 43 Jefferson Co Airport C643174605663
Nederland High School C1035 163575458
SETRPC 40 Sabine Pass C640/C1654167625160
Hamshire C64/C654165625661
West Orange C9/A141264625359
Port Arthur West C28/A128/A228166575559
Beaumont-Downtown C2/A112/C2002 265595660
Audubon C38163635861
Austin North Hills Drive C3/A32226346 *5956
Seabrook Friendship Park C45164644959
Houston Westhollow C410/C3003173665364
Hou.DeerPrk2 C35/235/1001/AFH139FP239176735568
Houston Harvard Street C4171  59 
Houston North Wayside C405/C1033167615360
Houston Monroe C406171625362
Conroe Relocated C78/A321174756571
Houston East C1/G316270675865
Channelview C15/AH115 367625260
Lake Jackson C1016 163655862
Baytown Garth C1017169665663
Park Place C416172705967
Houston Croquet C409275665665
Houston Aldine C8/AF108/X150 281686270
Houston Bayland Park C53/A146 1807360 **71
Clinton C403/C304/AH113 373715365
Northwest Harris Co. C26/A110/X154273716168
Manvel Croix Park C84179705969
Lang C408275695767
Galveston 99th St. C1034/A320/X183179686069
Lynchburg Ferry C1015/A165 168615160
San Antonio
Camp Bullis C58 169746970
Calaveras Lake C59163666063
San Antonio Northwest C23275696670
Corpus Christi-Victoria
Victoria C87162605559
Corpus Christi West C4262615459
Corpus Christi Tuloso C21158645659
Lower Rio Grande Valley
Mission C43/AP143153555755
Harlingen Teege C1023159535154
Laredo Vidaurri C44/AFGP144/P244159605959
* 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 2021 (101 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.