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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 C1051162634556
Rockwall Heath C69164644256
Kaufman C71/A304/X071163653855
Dallas Executive Airport C402167674860
Parker County C76168684560
Granbury C73/C681166624357
Grapevine Fairway C70/A301/X182171774263
Dallas North No.2 C63/C679173694562
Pilot Point C1032173714864
Dallas Hinton St. C401/C60/AH161 365644357
Denton Airport South C56/A163/X157171714963
Ft. Worth Northwest C13/AH302 267754662
Midlothian OFW C52/A137163614757
Frisco C31/C680176704563
Italy C1044/A323159604755
Cleburne Airport C77/C682173674762
Arlington Municipal Airport C61164684559
Keller C17271714361
Greenville C1006/A198161614656
Eagle Mountain Lake C75 175764966
Longview C19/A127/C644267555057
Tyler Airport Relocated C82167604958
Karnack C85/AFHP303162554554
El Paso-Juarez
Ivanhoe C414/F514170684661
El Paso UTEP C12/A125/X151/G125275794265
Socorro Hueco C49/F312167744361
Skyline Park C72172714663
Chamizal C41/AH126 173724463
Ascarate Park SE C37/A332/A172/X159164694057
Waco Mazanec C1037163634757
Temple Georgia C1045163645059
Killeen Skylark Field C1047167634859
Beaumont-Port Arthur
SETRPC 43 Jefferson Co Airport C643174604760
Nederland High School C1035 163574555
SETRPC 40 Sabine Pass C640/C1654167624558
Hamshire C64/C654165624657
West Orange C9/A141264624456
Port Arthur West C28/A128/A228166574656
Beaumont-Downtown C2/A112/C2002 265594656
Audubon C38163634456
Austin North Hills Drive C3/A32226346 *4651
Seabrook Friendship Park C45164643955
Houston Westhollow C410/C3003173663959
Hou.DeerPrk2 C35/235/1001/AFH139FP239176734564
Houston Harvard Street C4171  41 ** 
Houston North Wayside C405167613955
Houston Monroe C406171624559
Conroe Relocated C78/A321174755066
Houston East C1/G316270674460
Channelview C15/AH115 367624357
Lake Jackson C1016 163654557
Baytown Garth C1017169664760
Park Place C416172704261
Houston Croquet C409275664461
Houston Aldine C8/AF108/X150 281684464
Houston Bayland Park C53/A146 180734666
Clinton C403/C304/AH113 373714161
Northwest Harris Co. C26/A110/X154273714362
Manvel Croix Park C84179704564
Lang C408275694563
Galveston 99th St. C1034/A320/X183179685266
Lynchburg Ferry C1015/A165 168614056
San Antonio
Camp Bullis C58 169745365
Calaveras Lake C59163664859
San Antonio Northwest C23275694763
Corpus Christi-Victoria
Victoria C87162604656
Corpus Christi West C4262614355
Corpus Christi Tuloso C21158644656
Lower Rio Grande Valley
Mission C43/AP143153554350
Harlingen Teege C1023159534552
Laredo Vidaurri C44/AFGP144/P244159604454
* 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 (44 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.