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Eight-Hour Ozone High Value Days for 2024
as of July 13

The table below lists the daily maximum eight-hour ozone concentrations measured which meet or exceed 71 parts per billion in 2024 in each community where the TCEQ measures ozone. This information is updated hourly. Concentrations are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.) Times shown are in 24-hour format and are Local Standard Time. Our convention is that the time reflects the beginning of the eight-hour average. All ozone measurements are in parts per billion.

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YearSort ByReport Format
Highlight with AQI colors
2024 Sorted by Maximum Value
LocationRegionCAMSAQSDateTimeValuePOC
Elm Creek Elementary C501 13 50148_029_0501May 26 202413:001221 N
Bunker Hill Village C562 12 56248_201_0562June 7 202409:001091 N
West Houston C554 12 55448_201_0554June 7 202409:001081 N
Houston Harvard Street C417 12 41748_201_0417June 7 202409:001061
Elm Creek Elementary C501 13 50148_029_0501May 28 202406:001031 N
Meyer Park C561 12 56148_201_0561May 15 202410:001031 N
Katy Park C559 12 55948_201_0559June 7 202410:001021 N
Houston Bayland Park C53/A146 12 5348_201_0055June 7 202410:001001
Mercer Arboretum C557 12 55748_201_0557May 18 202411:001001 N
Houston Westhollow C410/C3003 12 41048_201_0066June 7 202410:00991
UH Moody Tower C695 12 69548_201_0695June 7 202410:00991 N
Houston Aldine C8/AF108/X150 12 848_201_0024May 15 202411:00982
Houston East C1/G316 12 148_201_1034May 15 202409:00982
Northwest Harris Co. C26/A110/X154 12 2648_201_0029May 15 202411:00962
Pilot Point C1032 4 103248_121_1032June 14 202410:00951
Mercer Arboretum C557 12 55748_201_0557May 15 202409:00951 N
Seabrook Friendship Park C45 12 4548_201_1050July 9 202410:00951
Houston North Wayside C405/C1033 12 40548_201_0046May 15 202411:00941
Atascocita C560 12 56048_201_0560May 18 202410:00941 N
Eagle Mountain Lake C75 4 7548_439_0075June 6 202411:00931
Denton Airport South C56/A163/X157 4 5648_121_0034June 14 202412:00921
Conroe Relocated C78/A321 12 7848_339_0078May 15 202410:00921
Keller C17 4 1748_439_2003June 6 202411:00922
Manvel Croix Park C84 12 8448_039_1004June 6 202410:00911
Houston Aldine C8/AF108/X150 12 848_201_0024May 18 202411:00912
HRM-3 Haden Road C603/A114 12 60348_201_0803May 15 202410:00911 N
Clinton C403/C304/AH113 12 40348_201_1035June 7 202410:00913
Texas City 34th St. C620 12 62048_167_0056May 15 202410:00901 N
Houston Bayland Park C53/A146 12 5348_201_0055June 14 202410:00901
Ft. Worth Northwest C13/AH302 4 1348_439_1002June 6 202411:00892
Frisco C31/C680 4 3148_085_0005July 11 202411:00881
Lang C408 12 40848_201_0047June 7 202409:00872
CAPCOG Round Rock Brushy Creek W C1620 11 162048_491_1620May 8 202412:00871 N
Heritage Middle School C622 13 62248_029_0622May 14 202411:00861 N
Atascocita C560 12 56048_201_0560May 15 202410:00861 N
Lynchburg Ferry C1015/A165 12 101548_201_1015May 15 202410:00861
Houston Harvard Street C417 12 41748_201_0417May 15 202408:00851
Tom Bass C558 12 55848_201_0558June 6 202409:00851 N
Bunker Hill Village C562 12 56248_201_0562June 14 202410:00851 N
Eagle Mountain Lake C75 4 7548_439_0075June 27 202411:00851
Denton Airport South C56/A163/X157 4 5648_121_0034June 6 202410:00841
Pilot Point C1032 4 103248_121_1032July 11 202411:00841
Camp Bullis C58 13 5848_029_0052June 7 202410:00831
Elm Creek Elementary C501 13 50148_029_0501June 7 202409:00831 N
Pilot Point C1032 4 103248_121_1032June 7 202410:00831
Pilot Point C1032 4 103248_121_1032June 13 202411:00831
Lang C408 12 40848_201_0047May 15 202410:00832
Houston Bayland Park C53/A146 12 5348_201_0055June 6 202409:00831
Houston Westhollow C410/C3003 12 41048_201_0066June 14 202410:00831
Park Place C416 12 41648_201_0416June 7 202410:00831
Park Place C416 12 41648_201_0416June 14 202411:00831
Huffman Wolf Road C563 12 56348_201_0563May 15 202409:00831 N
Nederland 17th Street C1035 10 103548_245_1035May 15 202410:00831
Channelview C15/AH115 12 1548_201_0026May 15 202410:00823
Houston Croquet C409 12 40948_201_0051June 7 202410:00822
Houston Croquet C409 12 40948_201_0051June 14 202410:00822
Crosby Library C553 12 55348_201_0553May 15 202408:00821 N
West Houston C554 12 55448_201_0554June 14 202410:00821 N
Houston East C1/G316 12 148_201_1034June 7 202410:00822
SETRPC Port Arthur C628 10 62848_245_0628May 15 202410:00821 N
Eagle Mountain Lake C75 4 7548_439_0075June 14 202412:00821
Grapevine Fairway C70/A301/X182 4 7048_439_3009June 14 202411:00821
Arlington Municipal Airport C61 4 6148_439_3011July 10 202411:00821
Frisco C31/C680 4 3148_085_0005June 14 202411:00811
Texas City 34th St. C620 12 62048_167_0056June 14 202413:00811 N
Houston Harvard Street C417 12 41748_201_0417June 13 202411:00811
West Houston C554 12 55448_201_0554June 13 202410:00811 N
Bunker Hill Village C562 12 56248_201_0562June 13 202408:00811 N
UH Moody Tower C695 12 69548_201_0695June 14 202411:00811 N
Clinton C403/C304/AH113 12 40348_201_1035May 15 202411:00813
Hou.DeerPrk2 C35/235/1001/AFH139FP239 12 3548_201_1039May 15 202410:00811
Fair Oaks Ranch C502 13 50248_029_0502June 7 202409:00801 N
Oyster Creek C1607 12 160748_039_1607June 6 202410:00801 N
Dallas North No.2 C63/C679 4 6348_113_0075July 11 202410:00801
Dallas Executive Airport C402 4 40248_113_0087June 6 202409:00801
Chamizal C41/AH126 6 4148_141_0044June 12 202409:00801
Park Place C416 12 41648_201_0416May 15 202411:00801
Waco Mazanec C1037 9 103748_309_1037July 10 202411:00801
Grapevine Fairway C70/A301/X182 4 7048_439_3009July 11 202411:00801
Arlington Municipal Airport C61 4 6148_439_3011July 11 202410:00801
San Antonio Northwest C23 13 2348_029_0032June 7 202409:00792
Government Canyon C1610 13 161048_029_1610May 9 202411:00791 N
Lake Jackson C1016 12 101648_039_1016June 6 202410:00791
AACOG City of Garden Ridge C505 13 50548_091_0505June 7 202409:00791 N
Dallas Hinton St. C401/C60/AH161 4 40148_113_0069May 31 202411:00793
Dallas Hinton St. C401/C60/AH161 4 40148_113_0069June 14 202411:00793
Denton Airport South C56/A163/X157 4 5648_121_0034July 11 202414:00791
Chamizal C41/AH126 6 4148_141_0044June 15 202411:00791
Texas City 34th St. C620 12 62048_167_0056May 14 202411:00791 N
Longview C19/A127/C644 5 1948_183_0001June 14 202410:00792
Lang C408 12 40848_201_0047June 14 202411:00792
Houston Bayland Park C53/A146 12 5348_201_0055June 13 202410:00791
Houston Harvard Street C417 12 41748_201_0417June 14 202411:00791
Houston East C1/G316 12 148_201_1034May 27 202410:00792
Beaumont-Downtown C2/A112/C2002 10 248_245_0009May 15 202410:00792
Conroe Relocated C78/A321 12 7848_339_0078June 8 202410:00791
Keller C17 4 1748_439_2003June 14 202412:00792
Arlington Municipal Airport C61 4 6148_439_3011June 6 202410:00791
Laredo College C44 16 4448_479_0016May 18 202410:00791 N
Heritage Middle School C622 13 62248_029_0622June 7 202410:00781 N
Dallas Executive Airport C402 4 40248_113_0087May 31 202411:00781
Dallas Executive Airport C402 4 40248_113_0087July 11 202411:00781
Pilot Point C1032 4 103248_121_1032July 12 202411:00781
Houston Croquet C409 12 40948_201_0051June 6 202410:00782
Houston Westhollow C410/C3003 12 41048_201_0066June 13 202410:00781
Houston Harvard Street C417 12 41748_201_0417May 27 202411:00781
West Houston C554 12 55448_201_0554May 15 202410:00781 N
Clinton C403/C304/AH113 12 40348_201_1035May 27 202411:00783
Dripping Springs School C614 11 61448_209_0614June 7 202411:00781 N
Hamshire C64/C654 10 6448_245_0022June 7 202411:00781
Nederland 17th Street C1035 10 103548_245_1035June 7 202410:00781
Conroe Relocated C78/A321 12 7848_339_0078May 18 202413:00781
Corsicana Airport C1051 4 105148_349_1051July 9 202412:00781
Keller C17 4 1748_439_2003July 11 202411:00782
Elm Creek Elementary C501 13 50148_029_0501June 6 202412:00771 N
Elm Creek Elementary C501 13 50148_029_0501June 10 202412:00771 N
Manvel Croix Park C84 12 8448_039_1004June 14 202410:00771
Dallas Hinton St. C401/C60/AH161 4 40148_113_0069June 6 202410:00773
Dallas Hinton St. C401/C60/AH161 4 40148_113_0069July 11 202411:00773
Denton Airport South C56/A163/X157 4 5648_121_0034June 12 202410:00771
Skyline Park C72 6 7248_141_0058June 12 202408:00771
UH Moody Tower C695 12 69548_201_0695May 15 202411:00771 N
SETRPC 43 Jefferson Co Airport C643 10 64348_245_0102June 7 202411:00771
Eagle Mountain Lake C75 4 7548_439_0075June 12 202411:00771
Fair Oaks Ranch C502 13 50248_029_0502July 11 202411:00761 N
Government Canyon C1610 13 161048_029_1610May 14 202412:00761 N
Dallas North No.2 C63/C679 4 6348_113_0075June 14 202411:00761
Dallas North No.2 C63/C679 4 6348_113_0075July 10 202410:00761
Denton Airport South C56/A163/X157 4 5648_121_0034June 13 202412:00761
Pilot Point C1032 4 103248_121_1032May 15 202410:00761
Pilot Point C1032 4 103248_121_1032June 15 202409:00761
Texas City 34th St. C620 12 62048_167_0056April 4 202411:00761 N
Seguin Outdoor Learning Center C506 13 50648_187_0506June 7 202409:00761 N
Park Place C416 12 41648_201_0416June 6 202410:00761
Sheldon C551 12 55148_201_0551May 15 202410:00761 N
Houston East C1/G316 12 148_201_1034July 1 202410:00762
Dripping Springs School C614 11 61448_209_0614May 15 202409:00761 N
Cleburne Airport C77/C682 4 7748_251_0003June 5 202412:00761
West Orange C9/A141 10 948_361_1001May 15 202412:00762
Grapevine Fairway C70/A301/X182 4 7048_439_3009June 6 202410:00761
Calaveras Lake C59 13 5948_029_0059May 14 202411:00751
Frisco C31/C680 4 3148_085_0005June 13 202411:00751
Frisco C31/C680 4 3148_085_0005July 10 202410:00751
Dallas Hinton St. C401/C60/AH161 4 40148_113_0069July 10 202411:00753
Socorro Hueco C49/F312 6 4948_141_0057June 12 202411:00751
Ojo De Agua C1021/FG121/FG221 6 102148_141_1021June 13 202410:00751
Galveston 99th St. C1034/A320/X183 12 103448_167_1034May 15 202412:00751
Houston Bayland Park C53/A146 12 5348_201_0055May 15 202411:00751
Houston Westhollow C410/C3003 12 41048_201_0066June 6 202410:00751
Bunker Hill Village C562 12 56248_201_0562May 15 202410:00751 N
Huffman Wolf Road C563 12 56348_201_0563May 18 202410:00751 N
Clinton C403/C304/AH113 12 40348_201_1035June 14 202411:00753
Clinton C403/C304/AH113 12 40348_201_1035July 1 202410:00753
Conroe Relocated C78/A321 12 7848_339_0078July 2 202412:00751
Eagle Mountain Lake C75 4 7548_439_0075May 29 202411:00751
Ft. Worth Northwest C13/AH302 4 1348_439_1002May 29 202411:00752
Ft. Worth Northwest C13/AH302 4 1348_439_1002July 11 202411:00752
Killeen Skylark Field C1047 9 104748_027_1047June 6 202411:00741
Heritage Middle School C622 13 62248_029_0622June 6 202411:00741 N
Dallas Executive Airport C402 4 40248_113_0087July 10 202411:00741
Denton Airport South C56/A163/X157 4 5648_121_0034June 7 202410:00741
Ascarate Park SE C37/A332/A172/X159 6 3748_141_0055June 12 202409:00741
Skyline Park C72 6 7248_141_0058July 10 202410:00741
Galveston 99th St. C1034/A320/X183 12 103448_167_1034May 14 202413:00741
Channelview C15/AH115 12 1548_201_0026May 18 202410:00743
La Porte Sylvan Beach C556 12 55648_201_0556May 15 202410:00741 N
Mercer Arboretum C557 12 55748_201_0557April 12 202410:00741 N
Mercer Arboretum C557 12 55748_201_0557May 19 202410:00741 N
Tom Bass C558 12 55848_201_0558June 7 202409:00741 N
Dripping Springs School C614 11 61448_209_0614July 11 202411:00741 N
SETRPC 43 Jefferson Co Airport C643 10 64348_245_0102May 15 202409:00741
SETRPC Port Arthur C628 10 62848_245_0628June 12 202409:00741 N
Corsicana Airport C1051 4 105148_349_1051May 14 202411:00741
Eagle Mountain Lake C75 4 7548_439_0075July 11 202412:00741
Keller C17 4 1748_439_2003May 29 202411:00742
Arlington Municipal Airport C61 4 6148_439_3011July 9 202411:00741
San Antonio Northwest C23 13 2348_029_0032May 14 202412:00732
Calaveras Lake C59 13 5948_029_0059June 7 202409:00731
Elm Creek Elementary C501 13 50148_029_0501May 14 202412:00731 N
Elm Creek Elementary C501 13 50148_029_0501May 27 202404:00731 N
Pilot Point C1032 4 103248_121_1032July 10 202411:00731
Chamizal C41/AH126 6 4148_141_0044June 16 202409:00731
Socorro Hueco C49/F312 6 4948_141_0057June 15 202411:00731
Ojo De Agua C1021/FG121/FG221 6 102148_141_1021July 9 202410:00731
Ojo De Agua C1021/FG121/FG221 6 102148_141_1021July 10 202409:00731
Houston Aldine C8/AF108/X150 12 848_201_0024April 12 202410:00732
Northwest Harris Co. C26/A110/X154 12 2648_201_0029June 7 202410:00732
Houston Harvard Street C417 12 41748_201_0417June 6 202409:00731
Sheldon C551 12 55148_201_0551May 18 202410:00731 N
UH Moody Tower C695 12 69548_201_0695June 6 202410:00731 N
Port Arthur West C28/A128/A228 10 2848_245_0011May 15 202412:00731
Conroe Relocated C78/A321 12 7848_339_0078April 5 202410:00731
UH WG Jones Forest C698 12 69848_339_0698April 12 202412:00731 N
Corsicana Airport C1051 4 105148_349_1051July 10 202410:00731
Killeen Skylark Field C1047 9 104748_027_1047July 11 202410:00721
Camp Bullis C58 13 5848_029_0052June 6 202411:00721
Fair Oaks Ranch C502 13 50248_029_0502June 6 202411:00721 N
Denton Airport South C56/A163/X157 4 5648_121_0034May 18 202411:00721
Chamizal C41/AH126 6 4148_141_0044July 10 202409:00721
Socorro Hueco C49/F312 6 4948_141_0057June 25 202410:00721
Skyline Park C72 6 7248_141_0058June 15 202411:00721
Ojo De Agua C1021/FG121/FG221 6 102148_141_1021June 12 202408:00721
Ojo De Agua C1021/FG121/FG221 6 102148_141_1021July 6 202412:00721
Houston Aldine C8/AF108/X150 12 848_201_0024June 11 202408:00722
Northwest Harris Co. C26/A110/X154 12 2648_201_0029April 30 202411:00722
Northwest Harris Co. C26/A110/X154 12 2648_201_0029May 19 202410:00722
Lang C408 12 40848_201_0047May 27 202411:00722
Houston Harvard Street C417 12 41748_201_0417June 10 202411:00721
West Houston C554 12 55448_201_0554June 22 202409:00721 N
Meyer Park C561 12 56148_201_0561April 30 202410:00721 N
Bunker Hill Village C562 12 56248_201_0562June 6 202409:00721 N
Dripping Springs School C614 11 61448_209_0614May 14 202412:00721 N
Hamshire C64/C654 10 6448_245_0022May 15 202410:00721
SETRPC 40 Sabine Pass C640/C1654 10 64048_245_0101June 6 202411:00721
Kaufman C71/A304/X071 4 7148_257_0005July 10 202410:00721
Conroe Relocated C78/A321 12 7848_339_0078May 20 202410:00721
Ft. Worth Northwest C13/AH302 4 1348_439_1002June 27 202410:00722
Ft. Worth Northwest C13/AH302 4 1348_439_1002July 10 202411:00722
Keller C17 4 1748_439_2003July 10 202412:00722
Grapevine Fairway C70/A301/X182 4 7048_439_3009July 10 202410:00721
CAPCOG Elgin C1613 11 161348_021_1613May 8 202411:00711 N
Killeen Skylark Field C1047 9 104748_027_1047May 15 202409:00711
San Antonio Northwest C23 13 2348_029_0032May 29 202412:00712
San Antonio Northwest C23 13 2348_029_0032June 6 202411:00712
Elm Creek Elementary C501 13 50148_029_0501June 14 202412:00711 N
Dallas Executive Airport C402 4 40248_113_0087June 14 202411:00711
Italy C1044/A323 4 104448_139_1044July 9 202411:00711
Chamizal C41/AH126 6 4148_141_0044May 23 202411:00711
Socorro Hueco C49/F312 6 4948_141_0057June 27 202409:00711
Skyline Park C72 6 7248_141_0058July 11 202411:00711
Galveston 99th St. C1034/A320/X183 12 103448_167_1034April 4 202412:00711
New Braunfels Airport C504 13 50448_187_0504June 7 202410:00711 N
Houston North Wayside C405/C1033 12 40548_201_0046May 27 202411:00711
Katy Park C559 12 55948_201_0559June 13 202410:00711 N
Wallisville Road C617 12 61748_201_0617May 15 202410:00711 N
HRM-3 Haden Road C603/A114 12 60348_201_0803June 7 202410:00711 N
Baytown Garth C1017 12 101748_201_1017May 15 202410:00711
Hou.DeerPrk2 C35/235/1001/AFH139FP239 12 3548_201_1039June 14 202412:00711
Kaufman C71/A304/X071 4 7148_257_0005May 14 202411:00711
Kaufman C71/A304/X071 4 7148_257_0005June 5 202410:00711
Waco Mazanec C1037 9 103748_309_1037July 11 202411:00711
Conroe Relocated C78/A321 12 7848_339_0078April 12 202412:00711
Conroe Relocated C78/A321 12 7848_339_0078April 13 202410:00711
Conroe Relocated C78/A321 12 7848_339_0078April 30 202410:00711
Corsicana Airport C1051 4 105148_349_1051June 5 202411:00711
Grapevine Fairway C70/A301/X182 4 7048_439_3009June 13 202411:00711
POC (Parameter Occurrence Code): a code used to correctly separate data from multiple instruments at one site.
 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.