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Daily Maximum Eight-Hour Ozone Averages for January 2021

The table below lists the peak daily maximum eight-hour ozone concentrations measured in January 2021 in each community where the TCEQ measures ozone. Concentrations that are rated Moderate or higher are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.) All ozone measurements are in parts per billion.

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 with AQI colors
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Dallas-Fort Worth
Ft. Worth Northwest C13/AH302 2323536313028243024222933343937232Ft. Worth Northwest C13/AH302
Keller C172313434353531273028212932333535222Keller C17
Frisco C31/C6801303235393534222931232829343837211Frisco C31/C680
Midlothian OFW C52/A1371323739334032263026192534343637191Midlothian OFW C52/A137
Denton Airport South C56/A163/X1571333735NV3433303333223137384039191Denton Airport South C56/A163/X157
Arlington Municipal Airport C611323538263632263025202836363737191Arlington Municipal Airport C61
Dallas North No.2 C63/C6791323235353632242829222628343636161Dallas North No.2 C63/C679
Rockwall Heath C691283132363531252530212625323534191Rockwall Heath C69
Grapevine Fairway C70/A301/X1821303232333228262929232730303634211Grapevine Fairway C70/A301/X182
Kaufman C71/A304/X0711232836373433262526162429303332151Kaufman C71/A304/X071
Granbury C73/C6811313636343725283223273334343736211Granbury C73/C681
Eagle Mountain Lake C75 1NANANV403532293329253338384039231Eagle Mountain Lake C75
Parker County C761333734414326273229303536383938261Parker County C76
Cleburne Airport C77/C68213437393441NANV3426252934373837201Cleburne Airport C77/C682
Dallas Hinton St. C401/C60/AH161 3302933313119232828222224283534123Dallas Hinton St. C401/C60/AH161
Dallas Executive Airport C40213235393637302732292126NV3539NV221Dallas Executive Airport C402
Greenville C1006/A1981253636413429312632202830343836221Greenville C1006/A198
Pilot Point C10321313433393431252932213235343938261Pilot Point C1032
Italy C1044/A3231293641384027243031222436323737241Italy C1044/A323
Corsicana Airport C10511273743394032252830222034343635201Corsicana Airport C1051
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Longview C19/A127/C6442233541393224262630232235373837262Longview C19/A127/C644
Tyler Airport Relocated C821253946454032292931222131363838261Tyler Airport Relocated C82
Karnack C85/AFHP3031203038363328262628272232343636221Karnack C85/AFHP303
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
El Paso-Juarez
El Paso UTEP C12/A125/X151/G125231363525333428193126273030283432El Paso UTEP C12/A125/X151/G125
Ascarate Park SE C37/A332/A172/X159130303122253621203026272627222611Ascarate Park SE C37/A332/A172/X159
Chamizal C41/AH126 13238372134392621272628NV34293411Chamizal C41/AH126
Socorro Hueco C49/F3121NANANANANANANV283526282630203021Socorro Hueco C49/F312
Skyline Park C72134404239384330353527313029354021Skyline Park C72
Ivanhoe C414/F514133333130303925313327293032273771Ivanhoe C414/F514
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Waco Mazanec C10371333846424735283331232636333938201Waco Mazanec C1037
Temple Georgia C10451363846384931323329303535383939271Temple Georgia C1045
Killeen Skylark Field C10471333742374429303028253232353535231Killeen Skylark Field C1047
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Beaumont-Port Arthur
Beaumont-Downtown C2/A112/C2002 230324546373731312923263038NV38252Beaumont-Downtown C2/A112/C2002
West Orange C9/A1412292944443841293129252730384337222West Orange C9/A141
Port Arthur West C28/A128/A228130324647403731322926NV31394337231Port Arthur West C28/A128/A228
Hamshire C64/C6541313344464142313031252731394537241Hamshire C64/C654
SETRPC 40 Sabine Pass C640/C1654131324545403831NV29242723394237201SETRPC 40 Sabine Pass C640/C1654
SETRPC Mauriceville 42 C642/C311/C6651 N33355051444335353129NV34445342291SETRPC Mauriceville 42 C642/C311/C665
SETRPC 43 Jefferson Co Airport C6431323346484039323330262832404438231SETRPC 43 Jefferson Co Airport C643
Nederland High School C1035 1293145443937303228252829384436211Nederland High School C1035
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Austin North Hills Drive C3/A3222343544404131333031273327323737252Austin North Hills Drive C3/A322
Audubon C38136374342NV31343231243130363939261Audubon C38
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Houston East C1/G3162323444413740231929212023324131122Houston East C1/G316
Houston Aldine C8/AF108/X150 2323844434039273032242826344438232Houston Aldine C8/AF108/X150
Channelview C15/AH115 3313743403436262730232729304336213Channelview C15/AH115
Northwest Harris Co. C26/A110/X1542303643374134262929232730343735222Northwest Harris Co. C26/A110/X154
Hou.DeerPrk2 C35/235/1001/AFH139FP2391303639454143272931232727374536211Hou.DeerPrk2 C35/235/1001/AFH139FP239
Seabrook Friendship Park C451273039333836232328231928343931181Seabrook Friendship Park C45
Houston Bayland Park C53/A146 1333845424541283030242723364438211Houston Bayland Park C53/A146
Conroe Relocated C78/A3211323946425140243232252933364237251Conroe Relocated C78/A321
Manvel Croix Park C841333743414540292831222622374337211Manvel Croix Park C84
Clinton C403/C304/AH113 330354133383624253123NV21243329123Clinton C403/C304/AH113
Houston North Wayside C4051263138293233222227222421223231151Houston North Wayside C405
Houston Monroe C4061293338373736252126212120343933131Houston Monroe C406
Lang C4082323645393736262530232423344136212Lang C408
Houston Croquet C4092253043374438242330202216303930132Houston Croquet C409
Houston Westhollow C410/C30031273238344133222423182118293430181Houston Westhollow C410/C3003
Park Place C4161313543414139262532212520314235191Park Place C416
Sheldon C5511 N393241493833293527243025363434221Sheldon C551
Baytown Wetlands Center C5521 N283236363633242627202624293829141Baytown Wetlands Center C552
Crosby Library C5531 N313641393329222325192325223532221Crosby Library C553
West Houston C5541 N283339323932242625202423313433191West Houston C554
La Porte Sylvan Beach C5561 N323642384238302832252728364335211La Porte Sylvan Beach C556
Mercer Arboretum C5571 N293340343934242729222626313935171Mercer Arboretum C557
Tom Bass C5581 N323642404340262629222622364235191Tom Bass C558
Katy Park C5591 N323644344737283028242826323937241Katy Park C559
Atascocita C5601 N273239343734212526202424283733201Atascocita C560
Meyer Park C5611 N303644383935262929222728344136201Meyer Park C561
Bunker Hill Village C5621 N283339343833242324192118313632201Bunker Hill Village C562
Huffman Wolf Road C5631 N333845434441333132263033324539251Huffman Wolf Road C563
Wallisville Road C617 1 N344047454442313234273138324840261Wallisville Road C617
Texas City 34th St. C620 1 N353745NV5149363338313232455042261Texas City 34th St. C620
UH Moody Tower C6951 N323844444140282731222623344436251UH Moody Tower C695
UH WG Jones Forest C6981 N354452485141283436263236424642291UH WG Jones Forest C698
UH West Liberty C6991 N303541414039292829222730294235221UH West Liberty C699
Lynchburg Ferry C1015/A165 1283243333430232428212425323832141Lynchburg Ferry C1015/A165
Lake Jackson C1016 1343444414843302834242627404437271Lake Jackson C1016
Baytown Garth C10171323745434342293033242834314437231Baytown Garth C1017
Galveston 99th St. C1034/A320/X1831353750435551373537343031464539271Galveston 99th St. C1034/A320/X183
Oyster Creek C1607 1 N404051475749373541373234494845351Oyster Creek C1607
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
San Antonio
San Antonio Northwest C232384048432936363232303027353738162San Antonio Northwest C23
Camp Bullis C58 1424254503739413735333432NANANV251Camp Bullis C58
Calaveras Lake C591383948433236352834292629383838101Calaveras Lake C59
Heritage Middle School C6221 N38395047323535273330302841383791Heritage Middle School C622
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Corpus Christi-Victoria
Corpus Christi West C42383943363740233534343523364338132Corpus Christi West C4
Corpus Christi Tuloso C211394044363240363734313525384539191Corpus Christi Tuloso C21
Victoria C871383946403738353634273323344236171Victoria C87
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Lower Rio Grande Valley
Mission C43/AP1431273840453438363731283531354038141Mission C43/AP143
Harlingen Teege C1023130394038363335363329342936373581Harlingen Teege C1023
AreaMonitoring SitePOCJanuary 2021POCMonitoring Site
Laredo Vidaurri C44/AFGP144/P244141404336344036372726362428353621Laredo Vidaurri C44/AFGP144/P244
POC (Parameter Occurrence Code): a code used to correctly separate data from multiple instruments at one site.
NV - There are not enough valid eight-hour averages for this day (there must be eighteen valid eight-hour averages).
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.