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Peak Daily One-Hour Ozone Averages for April 2025

The table below lists the peak daily one-hour ozone concentrations measured in April 2025 in each community where the TCEQ measures ozone. Concentrations are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.) All ozone measurements are in parts per billion, and are truncated to an integer number.

The values that go into this table are calculated at 3:30 am each morning. Therefore, the current day will almost always have very low hourly averages that are not truly representative of local conditions for the day. Because of this, the report does not display the current day's data.

Use the selection boxes below to customize this report. You may select a different month, a different year, a different report format, and whether or not to include time on the report. Click on the Generate Report button once you have made your selections.

Month:Year:Report Format: Include time:
Include time
Highlight using AQI colors
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Dallas-Fort Worth
Ft. Worth Northwest C13/AH302 253614128354461657087627567706261564554537161524542473634392Ft. Worth Northwest C13/AH302
Keller C17251574229314453606873587162625458524445456457474443453433392Keller C17
Frisco C31/C680147524325313760647666526465614958494448455370514953513735421Frisco C31/C680
Denton Airport South C56/A163/X157147534027314153636558526860524860524046415971534551453532391Denton Airport South C56/A163/X157
Arlington Municipal Airport C61144493826303961627584567164725757514450506054484538423830361Arlington Municipal Airport C61
Dallas North No.2 C63/C679147523624293861627666546465744958484548535560494345443433401Dallas North No.2 C63/C679
Rockwall Heath C69137413521283462635959495654604754503848504953433840443130371Rockwall Heath C69
Grapevine Fairway C70/A301/X182147554227313961666675566965655460NA4444506165524447433630411Grapevine Fairway C70/A301/X182
Kaufman C71/A304/X071139353322323873697062576462575367524657575362474237463533461Kaufman C71/A304/X071
Granbury C73/C681157614128374855606293707365636957584653516349505039443541411Granbury C73/C681
Eagle Mountain Lake C75 154564331344457627074577363615358553943476958474344443433391Eagle Mountain Lake C75
Parker County C76159574631374752616072596961585758544153466952465047423439391Parker County C76
Cleburne Airport C77/C682148523825323960597480677363626357544750515651504835433433381Cleburne Airport C77/C682
Dallas Executive Airport C402143393625313966667877607066675658474651515857464638383431381Dallas Executive Airport C402
Greenville C1006/A198141443822NANANA676866515759635472554451535361424038383232371Greenville C1006/A198
Pilot Point C1032151574527344262737266537066595468564547445680504855523736411Pilot Point C1032
Italy C1044/A323138433722303767706860657062605455444555535151464833403731341Italy C1044/A323
Corsicana Airport C1051139382924313675687466597564565738494941575964485540523733461Corsicana Airport C1051
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Tyler-Longview-Marshall
Longview C19/A127/C644235272925263251718260545566535660555044425654403245403031392Longview C19/A127/C644
Tyler Airport Relocated C82137312933263253697362525961565865634843435659424041393744381Tyler Airport Relocated C82
Karnack C85/AFHP303134292925222543627161505466515166424339384453273144463333331Karnack C85/AFHP303
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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El Paso-Juarez
Ascarate Park SE C37/A332/A172/X159151515047464555434854615261465236275257556752434649485450481Ascarate Park SE C37/A332/A172/X159
Chamizal C41/AH126 152525047474548415045545966465546345559546049454949465552531Chamizal C41/AH126
Socorro Hueco C49/F312147504747475152496558595663595245325257566258495165585152521Socorro Hueco C49/F312
Skyline Park C72154565252524963515762726067565745345358576858525164545654561Skyline Park C72
Ivanhoe C414/F5141NANANANANANA46414648545054494335234347506052444457504546471Ivanhoe C414/F514
Ojo De Agua C1021/FG121/FG221147494747484047454860635260465142294853505847444548455047501Ojo De Agua C1021/FG121/FG221
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Waco
Waco Mazanec C1037141383723314166737777644068716061515250585754545237453835371Waco Mazanec C1037
Temple Georgia C1045139424120284056667672647163695751484644556146474839413736381Temple Georgia C1045
Killeen Skylark Field C1047145454321304556687776677765755954575147596447525044474043481Killeen Skylark Field C1047
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Beaumont-Port Arthur
Beaumont-Downtown C2/A112/C2002 223252827282642555958566052525262483847413231404035472931332Beaumont-Downtown C2/A112/C2002
West Orange C9/A141221202424252238545761525651534859413743373131413335352326322West Orange C9/A141
Port Arthur West C28/A128/A228124222624262439575753535349505055463543353331323635382629311Port Arthur West C28/A128/A228
Hamshire C64/C654122192322253044546059585552525860433743393128333533392625301Hamshire C64/C654
SETRPC Port Arthur C6281 N33283232323050716865646355595864554150454038414343463331NA1SETRPC Port Arthur C628
SETRPC 40 Sabine Pass C640/C1654132212827292845656458635848535255483441393534343333332731331SETRPC 40 Sabine Pass C640/C1654
SETRPC Mauriceville 42 C642/C311/C6651 N21202422242541515859516053504959463943373231333540372316NA1SETRPC Mauriceville 42 C642/C311/C665
SETRPC 43 Jefferson Co Airport C643123222625262643595856565748505158453541383130343734382628321SETRPC 43 Jefferson Co Airport C643
Nederland 17th Street C1035124232725272643575960555952525261493745403334403936422730331Nederland 17th Street C1035
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Austin
Austin North Hills Drive C3/A322237445438274150666870656657605245434141556543423839393437352Austin North Hills Drive C3/A322
Audubon C38137405834284352627073666759615546454444546744404043413539381Audubon C38
Dripping Springs School C6141 N41465538315065798275827666666451484545698242423843413842451Dripping Springs School C614
Lockhart C16041 N31344035325064747979727165704847464344616839433738373437341Lockhart C1604
St. Edwards University C16051 N4043524034526478747277716360564745444762704144424023NANANA1St. Edwards University C1605
CAPCOG Bastrop CAMS16121 N38364231284257686765656660575450434346586845472732393537331CAPCOG Bastrop CAMS1612
CAPCOG Elgin C16131 N35354230264361716864686560565548414242636842433839373333331CAPCOG Elgin C1613
CAPCOG East Austin C16191 N33394434254151686567676557575243424042556641413737353335331CAPCOG East Austin C1619
CAPCOG Round Rock Brushy Creek W C16201 N3242513615NA546768736166576152464343445562434241263834NA351CAPCOG Round Rock Brushy Creek W C1620
CAPCOG Taylor Murphy Park C16291 N22275945415667838180777972654746404039555740384035342932311CAPCOG Taylor Murphy Park C1629
CAPCOG Lake Kyle Park C16301 N33454738304452726665686659585145444245566641363639373638361CAPCOG Lake Kyle Park C1630
CAPCOG San Marcos Staples Road C16751 N56577275243447666266746759605555586163606858636468645856301CAPCOG San Marcos Staples Road C1675
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Houston-Galveston-Brazoria
Houston East C1/G316221252824233450666668606750545064413943395135424439533230282Houston East C1/G316
Houston Aldine C8/AF108/X150 223263026253656687676647954615173484447435443425044653732282Houston Aldine C8/AF108/X150
Channelview C15/AH115 323242625243655706368636052564861423941395632354343503227273Channelview C15/AH115
Northwest Harris Co. C26/A110/X154228283230263661677877658153645966464348456650445148553934312Northwest Harris Co. C26/A110/X154
Hou.DeerPrk2 C35/235/1001/AFH139FP239130232725253655666260646147524960393541394534424137502927271Hou.DeerPrk2 C35/235/1001/AFH139FP239
Seabrook Friendship Park C45128232724243653725856646042474258363239363828433636442724261Seabrook Friendship Park C45
Houston Bayland Park C53/A146 12829322826365672706574694755446041NANANANANANA4541443529281Houston Bayland Park C53/A146
Conroe Relocated C78/A321124283632253254638494609762715178574852483956455261584541331Conroe Relocated C78/A321
Manvel Croix Park C84123252623253656676255746345494354393541394231463835383026251Manvel Croix Park C84
Clinton C403/C304/AH113 319212119213252675555635945444555343541384128373832462924243Clinton C403/C304/AH113
Houston North Wayside C405/C1033119202319202946576260216242464658373540364634374035522723221Houston North Wayside C405/C1033
Houston Monroe C406121222322233350665954605944473952353339384428373233362824241Houston Monroe C406
Lang C408222242724243350646966556646554458393542404838383940453228252Lang C408
Houston Croquet C409227283126273556746861746947534459423945434836464139433227262Houston Croquet C409
Houston Westhollow C410/C3003123242726233455666766706848514355383743415536394139423429261Houston Westhollow C410/C3003
Park Place C416123242624253351656356676547524757413844424733443937443429271Park Place C416
Houston Harvard Street C417123242724243248646563616345514557413743404636414239443430261Houston Harvard Street C417
Sheldon C5511 N22222321223554666170616446514357383439345630303835472923211Sheldon C551
Baytown Wetlands Center C5521 N23222220203450645558605546514658383440354828423635412927261Baytown Wetlands Center C552
Crosby Library C5531 N212223212121NANANA8258675060466141NANANANANANA3942433329261Crosby Library C553
West Houston C5541 N26263027263762697673707851564762444148446642444543483631281West Houston C554
La Porte Sylvan Beach C5561 N29202521223452715755585842494858363237353828423635422425261La Porte Sylvan Beach C556
Mercer Arboretum C5571 N27273126263860698790698955725680504450465952385648693934301Mercer Arboretum C557
Tom Bass C5581 N27272727273858726962767150554659424047432928423741403328271Tom Bass C558
Katy Park C5591 N25242723243455646761666747524654393644396938404040393327251Katy Park C559
Atascocita C5601 N22242517NANANANA74776180475610NA423846406142374846573730251Atascocita C560
Meyer Park C5611 N26273127243558687785647958635867454144405645404645573632291Meyer Park C561
Bunker Hill Village C5621 N23242623223455687270707249544660403744425137424139443328271Bunker Hill Village C562
Huffman Wolf Road C5631 N24273027263754637493577459684764494447416038434445493632301Huffman Wolf Road C563
HRM-3 Haden Road C603/A114 1 N25242423233553676469626550545061403640385133344138523018NA1HRM-3 Haden Road C603/A114
Wallisville Road C617 1 N30283127283654655965606248565061423844405235454444463325NA1Wallisville Road C617
Texas City 34th St. C620 1 N35232525253956695755686249515158393442384032443736402821NA1Texas City 34th St. C620
Lynchburg Ferry C1015/A165 128272726263448586063515750554861423741394630393740473127281Lynchburg Ferry C1015/A165
Lake Jackson C1016 12927282526365664595676574853635039NANANA4534504141383031291Lake Jackson C1016
Baytown Garth C1017130293127283652646068596349585062443846415235474545463330301Baytown Garth C1017
Galveston 99th St. C1034/A320/X183139313128304360666060786654565862454146414335NA4749423231311Galveston 99th St. C1034/A320/X183
Oyster Creek C1607 1 N342829282738596662617665525768554238464354355340424233NANA1Oyster Creek C1607
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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San Antonio
San Antonio Northwest C23236NA6644294450625763706355534941403739517137343739363733342San Antonio Northwest C23
Camp Bullis C58 142527052314955716778837162655847474344567943374245424240411Camp Bullis C58
Calaveras Lake C59140505544314654696361726857565145414043677233344038373939351Calaveras Lake C59
Elm Creek Elementary C5011 N37566244294553666262766757535343424141567534333839363838361Elm Creek Elementary C501
Fair Oaks Ranch C5021 N44466353304855686581817162675446474342587741404045404241411Fair Oaks Ranch C502
Bulverde Elementary C5031 N33374641243942585565636052544439393636476432313334313334341Bulverde Elementary C503
New Braunfels Airport C5041 N28343733253540575250575448463838363436475430302830303232331New Braunfels Airport C504
AACOG City of Garden Ridge C505 1 N40516347335149696364766957585146424042587339363741373840371AACOG City of Garden Ridge C505
Seguin Outdoor Learning Center C5061 N31394336263944625756626056514141403839536133343232333436331Seguin Outdoor Learning Center C506
Heritage Middle School C6221 N39495242314957746863777057535248424045728035374240394243371Heritage Middle School C622
CPS Pecan Valley C6781 N35495337284246655657676151494641383738556630303533313435321CPS Pecan Valley C678
Government Canyon C16101 N39516946314959706670827159555344434140618440343640373938371Government Canyon C1610
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Corpus Christi-Victoria
Corpus Christi West C4225333128394960736155586148535142403947434431413839353333292Corpus Christi West C4
Corpus Christi Tuloso C21124463829364960726458636346525142403847414229413839353435291Corpus Christi Tuloso C21
Victoria C87126252725294561666762646249545844403847434829453939353228271Victoria C87
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Lower Rio Grande Valley
Mission C43/AP143130443631434459726057635842475540403640364627333739343938301Mission C43/AP143
Harlingen Teege C1023128333430454159636159516345524643413847373928393939364137311Harlingen Teege C1023
AreaMonitoring SitePOCApril 2025POCMonitoring Site
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Laredo
Laredo College C441 N42616959445664756462596353515045464738664141343840424245371Laredo College C44
NA - Data not available.
 N - Data from this instrument does not meet EPA quality assurance criteria and cannot be used for regulatory purposes.

Interpreting the AQI

Air Quality Index

Each NAAQS pollutant has a separate AQI scale, with an AQI rating of 100 corresponding to the concentration of the Federal Standard for that pollutant. Additional information about the AQI and how it can be used is available from the EPA's AirNow web site.

Place your mouse pointer over the scale displayed above to view information about the Air Quality Index, and each of the rating levels.

The actual index calculation is different for each parameter measured and is specified by the EPA. The following table shows the various breakpoints used in calculating the AQI.

AQI Breakpoint Definitions
AQI Range 1hr Ozone
in ppm
8hr Ozone
in ppm
0 - 50 Not Defined 0 - 0.054
51 - 100 Not Defined 0.055 - 0.070
101 - 150 0.125 - 0.164 0.071 - 0.085
151 - 200 0.165 - 0.204 0.086 - 0.105
201 - 300 0.205 - 0.404 0.106 - 0.200
301 - 400 0.405 - 0.504 Not Defined
401 - 500 Not Defined Not Defined
500+ Not Defined Not Defined
  • The AQI for ozone is based on either the peak eight-hour running average since midnight OR the peak one-hour measurement since midnight.

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.