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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
1:10 pm CST
Dallas-Fort Worth
Corsicana Airport C1051162636262
Rockwall Heath C69164645962
Kaufman C71/A304/X071163655661
Dallas Executive Airport C402167676867
Parker County C76168686165
Granbury C73/C681166625962
Grapevine Fairway C70/A301/X182171776671
Dallas North No.2 C63/C679173696468
Pilot Point C1032173717673
Dallas Hinton St. C401/C60/AH161 365647467
Denton Airport South C56/A163/X157171717672
Ft. Worth Northwest C13/AH302 267757371
Midlothian OFW C52/A137163616262
Frisco C31/C680176706771
Italy C1044/A323159606059
Cleburne Airport C77/C682173676869
Arlington Municipal Airport C61164686866
Keller C17271717271
Greenville C1006/A198161615659
Eagle Mountain Lake C75 175767073
Longview C19/A127/C644267556060
Tyler Airport Relocated C82167605861
Karnack C85/AFHP303162555758
El Paso-Juarez
Ivanhoe C414/F514170686266
El Paso UTEP C12/A125/X151/G125275797175
Socorro Hueco C49/F312167747170
Ojo De Agua C1021/FG121/FG2211  68 ** 
Skyline Park C72172716669
Chamizal C41/AH126 173726770
Ascarate Park SE C37/A332/A172/X159164696064
Waco Mazanec C1037163636262
Temple Georgia C1045163646363
Killeen Skylark Field C1047167636665
Beaumont-Port Arthur
SETRPC 43 Jefferson Co Airport C643174605964
Nederland High School C1035 163575959
SETRPC 40 Sabine Pass C640/C1654167625962
Hamshire C64/C654165625962
West Orange C9/A141264626062
Port Arthur West C28/A128/A228166576061
Beaumont-Downtown C2/A112/C2002 265595860
Audubon C38163635861
Austin North Hills Drive C3/A32226346 *6156
Seabrook Friendship Park C45164645962
Houston Westhollow C410/C3003173666267
Hou.DeerPrk2 C35/235/1001/AFH139FP239176737273
Houston Harvard Street C4171  75 
Houston North Wayside C405/C1033167616464
Houston Monroe C406171626566
Conroe Relocated C78/A321174756571
Houston East C1/G316270677470
Channelview C15/AH115 367626263
Lake Jackson C1016 163656163
Baytown Garth C1017169666867
Park Place C416172707873
Houston Croquet C409275667672
Houston Aldine C8/AF108/X150 281686471
Houston Bayland Park C53/A146 180737475
Clinton C403/C304/AH113 373716971
Northwest Harris Co. C26/A110/X154273716268
Manvel Croix Park C84179707173
Lang C408275696569
Galveston 99th St. C1034/A320/X183179686269
Lynchburg Ferry C1015/A165 168616163
San Antonio
Camp Bullis C58 169747071
Calaveras Lake C59163666063
San Antonio Northwest C23275696770
Corpus Christi-Victoria
Victoria C87162605960
Corpus Christi West C4262615960
Corpus Christi Tuloso C21158646060
Lower Rio Grande Valley
Mission C43/AP143153555955
Harlingen Teege C1023159535254
Laredo Vidaurri C44/AFGP144/P244159606059
* 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 (154 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.