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Eight-Hour Ozone High Value Days for 2022
as of July 1

The table below lists the daily maximum eight-hour ozone concentrations measured which meet or exceed 71 parts per billion in 2022 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
2022 Sorted by Maximum Value
LocationRegionCAMSAQSDateTimeValuePOC
Denton Airport South C56/A163/X157 4 5648_121_0034June 30 202210:001001
Lockhart C1604 11 160448_055_1604May 26 202211:00981 N
Houston Harvard Street C417 12 41748_201_0417June 20 202210:00971
Houston East C1/G316 12 148_201_1034June 20 202207:00962
Grapevine Fairway C70/A301/X182 4 7048_439_3009June 30 202210:00931
West Houston C554 12 55448_201_0554June 20 202211:00921 N
Pilot Point C1032 4 103248_121_1032June 30 202210:00911
Northwest Harris Co. C26/A110/X154 12 2648_201_0029May 6 202211:00912
Lang C408 12 40848_201_0047June 20 202210:00902
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675May 26 202211:00901 N
CAPCOG Bastrop CAMS1612 11 161248_021_1612May 26 202211:00891 N
Galveston 99th St. C1034/A320/X183 12 103448_167_1034May 25 202213:00891
West Houston C554 12 55448_201_0554April 27 202211:00881 N
CAPCOG Lake Georgetown C690 11 69048_491_0690June 29 202212:00881 N
Clinton C403/C304/AH113 12 40348_201_1035June 20 202210:00873
Dripping Springs School C614 11 61448_209_0614June 29 202211:00871 N
Eagle Mountain Lake C75 4 7548_439_0075June 30 202210:00871
UH Launch Trailer C1611 12 161148_201_1611June 20 202210:00861 N
Grapevine Fairway C70/A301/X182 4 7048_439_3009May 27 202212:00861
UH Moody Tower C695 12 69548_201_0695June 20 202210:00851 N
Ft. Worth Northwest C13/AH302 4 1348_439_1002June 29 202211:00852
CAPCOG Elgin C1613 11 161348_021_1613May 26 202211:00841 N
Lang C408 12 40848_201_0047April 27 202211:00842
HRM-3 Haden Road C603/A114 12 60348_201_0803June 20 202210:00841 N
Granbury C73/C681 4 7348_221_0001June 29 202212:00841
Ft. Worth Northwest C13/AH302 4 1348_439_1002June 30 202210:00842
Frisco C31/C680 4 3148_085_0005June 30 202210:00831
Dripping Springs School C614 11 61448_209_0614March 2 202211:00831 N
Dripping Springs School C614 11 61448_209_0614May 26 202211:00831 N
Cleburne Airport C77/C682 4 7748_251_0003June 27 202210:00831
UH WG Jones Forest C698 12 69848_339_0698May 12 202211:00831 N
Ft. Worth Northwest C13/AH302 4 1348_439_1002May 27 202212:00832
Elm Creek Elementary C501 13 50148_029_0501June 29 202210:00821 N
Pilot Point C1032 4 103248_121_1032June 10 202213:00821
Houston Bayland Park C53/A146 12 5348_201_0055June 20 202210:00821
Houston Harvard Street C417 12 41748_201_0417April 27 202210:00821
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675June 29 202210:00821 N
Cleburne Airport C77/C682 4 7748_251_0003June 28 202212:00821
SETRPC Mauriceville 42 C642/C311/C665 10 64248_361_1100May 28 202211:00821 N
Eagle Mountain Lake C75 4 7548_439_0075May 27 202213:00821
Denton Airport South C56/A163/X157 4 5648_121_0034June 9 202212:00811
Keller C17 4 1748_439_2003June 30 202209:00812
Heritage Middle School C622 13 62248_029_0622June 29 202211:00801 N
Lockhart C1604 11 160448_055_1604June 29 202210:00801 N
Dallas Executive Airport C402 4 40248_113_0087May 27 202211:00801
Texas City 34th St. C620 12 62048_167_0056May 25 202211:00801 N
Cleburne Airport C77/C682 4 7748_251_0003June 29 202211:00801
Ft. Worth Northwest C13/AH302 4 1348_439_1002May 16 202211:00802
CAPCOG Round Rock Brushy Creek W C1620 11 162048_491_1620June 29 202212:00801 N
Killeen Skylark Field C1047 9 104748_027_1047June 29 202212:00791
San Antonio Northwest C23 13 2348_029_0032June 29 202211:00792
Denton Airport South C56/A163/X157 4 5648_121_0034June 22 202211:00791
Northwest Harris Co. C26/A110/X154 12 2648_201_0029April 27 202211:00792
Park Place C416 12 41648_201_0416June 20 202210:00791
Houston East C1/G316 12 148_201_1034June 16 202211:00792
SETRPC 40 Sabine Pass C640/C1654 10 64048_245_0101May 27 202211:00791
Calaveras Lake C59 13 5948_029_0059June 29 202210:00781
Denton Airport South C56/A163/X157 4 5648_121_0034June 10 202212:00781
Denton Airport South C56/A163/X157 4 5648_121_0034June 21 202210:00781
Baytown Garth C1017 12 101748_201_1017June 26 202210:00781
SETRPC 40 Sabine Pass C640/C1654 10 64048_245_0101May 28 202210:00781
Conroe Relocated C78/A321 12 7848_339_0078May 28 202210:00781
CAPCOG East Austin C1619 11 161948_453_1619June 29 202212:00781 N
UH Smith Point C1606 12 160648_071_1606May 25 202209:00771 N
Frisco C31/C680 4 3148_085_0005March 26 202212:00771
Frisco C31/C680 4 3148_085_0005June 10 202212:00771
Dallas Executive Airport C402 4 40248_113_0087May 16 202210:00771
Pilot Point C1032 4 103248_121_1032June 20 202209:00771
Pilot Point C1032 4 103248_121_1032June 23 202212:00771
Houston Harvard Street C417 12 41748_201_0417June 4 202211:00771
Houston Harvard Street C417 12 41748_201_0417June 16 202211:00771
Baytown Garth C1017 12 101748_201_1017May 26 202210:00771
Karnack C85/AFHP303 5 8548_203_0002June 21 202210:00771
Parker County C76 4 7648_367_0081May 16 202212:00771
Tyler Airport Relocated C82 5 8248_423_0007June 29 202211:00771
Eagle Mountain Lake C75 4 7548_439_0075June 29 202211:00771
Arlington Municipal Airport C61 4 6148_439_3011May 16 202211:00771
Arlington Municipal Airport C61 4 6148_439_3011May 27 202211:00771
Arlington Municipal Airport C61 4 6148_439_3011June 29 202211:00771
Dallas North No.2 C63/C679 4 6348_113_0075June 30 202209:00761
Mercer Arboretum C557 12 55748_201_0557May 12 202210:00761 N
Clinton C403/C304/AH113 12 40348_201_1035June 16 202211:00763
Hou.DeerPrk2 C35/235/1001/AFH139FP239 12 3548_201_1039June 26 202210:00761
Granbury C73/C681 4 7348_221_0001June 28 202210:00761
Keller C17 4 1748_439_2003May 27 202212:00762
CAPCOG Bastrop CAMS1612 11 161248_021_1612June 29 202213:00751 N
CAPCOG Elgin C1613 11 161348_021_1613June 29 202211:00751 N
Camp Bullis C58 13 5848_029_0052June 29 202211:00751
Fair Oaks Ranch C502 13 50248_029_0502June 29 202211:00751 N
Dallas North No.2 C63/C679 4 6348_113_0075May 27 202211:00751
Denton Airport South C56/A163/X157 4 5648_121_0034June 23 202212:00751
Chamizal C41/AH126 6 4148_141_0044June 30 202210:00751
Socorro Hueco C49/F312 6 4948_141_0057June 11 202210:00751
Houston North Wayside C405/C1033 12 40548_201_0046June 20 202210:00751
Houston Westhollow C410/C3003 12 41048_201_0066June 20 202211:00751
UH Launch Trailer C1611 12 161148_201_1611June 4 202211:00751 N
Dripping Springs School C614 11 61448_209_0614March 1 202211:00751 N
Dripping Springs School C614 11 61448_209_0614March 3 202211:00751 N
Dripping Springs School C614 11 61448_209_0614March 26 202211:00751 N
Dripping Springs School C614 11 61448_209_0614May 27 202212:00751 N
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675June 4 202211:00751 N
Grapevine Fairway C70/A301/X182 4 7048_439_3009June 17 202210:00751
Austin North Hills Drive C3/A322 11 348_453_0014June 29 202212:00752
City of Garden Ridge C505 13 50548_091_0505June 29 202211:00741 N
Denton Airport South C56/A163/X157 4 5648_121_0034May 6 202212:00741
Denton Airport South C56/A163/X157 4 5648_121_0034June 25 202211:00741
Pilot Point C1032 4 103248_121_1032June 25 202210:00741
Skyline Park C72 6 7248_141_0058June 30 202211:00741
Northwest Harris Co. C26/A110/X154 12 2648_201_0029June 20 202212:00742
West Houston C554 12 55448_201_0554April 14 202211:00741 N
Nederland 17th Street C1035 10 103548_245_1035May 28 202210:00741
Cleburne Airport C77/C682 4 7748_251_0003June 30 202209:00741
Kaufman C71/A304/X071 4 7148_257_0005March 2 202211:00741
Eagle Mountain Lake C75 4 7548_439_0075June 17 202213:00741
Temple Georgia C1045 9 104548_027_1045June 29 202211:00731
Frisco C31/C680 4 3148_085_0005June 23 202211:00731
Pilot Point C1032 4 103248_121_1032March 26 202211:00731
Texas City 34th St. C620 12 62048_167_0056May 26 202209:00731 N
Galveston 99th St. C1034/A320/X183 12 103448_167_1034March 1 202213:00731
Northwest Harris Co. C26/A110/X154 12 2648_201_0029June 21 202210:00732
Houston Bayland Park C53/A146 12 5348_201_0055June 4 202212:00731
West Houston C554 12 55448_201_0554May 26 202211:00731 N
Wallisville Road C617 12 61748_201_0617May 26 202210:00731 N
Houston East C1/G316 12 148_201_1034June 26 202210:00732
Hou.DeerPrk2 C35/235/1001/AFH139FP239 12 3548_201_1039May 26 202210:00731
Hou.DeerPrk2 C35/235/1001/AFH139FP239 12 3548_201_1039June 20 202208:00731
Dripping Springs School C614 11 61448_209_0614March 25 202212:00731 N
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675March 2 202211:00731 N
Conroe Relocated C78/A321 12 7848_339_0078May 17 202210:00731
UH WG Jones Forest C698 12 69848_339_0698June 23 202212:00731 N
West Orange C9/A141 10 948_361_1001May 28 202212:00732
Grapevine Fairway C70/A301/X182 4 7048_439_3009June 9 202211:00731
CAPCOG Lake Georgetown C690 11 69048_491_0690June 30 202209:00731 N
CAPCOG Bastrop CAMS1612 11 161248_021_1612June 4 202212:00721 N
CAPCOG Elgin C1613 11 161348_021_1613March 2 202210:00721 N
Killeen Skylark Field C1047 9 104748_027_1047May 27 202209:00721
Manvel Croix Park C84 12 8448_039_1004June 20 202210:00721
Dallas Executive Airport C402 4 40248_113_0087June 29 202210:00721
Denton Airport South C56/A163/X157 4 5648_121_0034March 3 202211:00721
Pilot Point C1032 4 103248_121_1032June 21 202210:00721
Pilot Point C1032 4 103248_121_1032June 24 202211:00721
Ascarate Park SE C37/A332/A172/X159 6 3748_141_0055June 30 202210:00721
Channelview C15/AH115 12 1548_201_0026June 20 202209:00723
Houston Croquet C409 12 40948_201_0051June 20 202210:00722
HRM-3 Haden Road C603/A114 12 60348_201_0803June 16 202211:00721 N
Baytown Garth C1017 12 101748_201_1017June 20 202209:00721
Houston East C1/G316 12 148_201_1034May 16 202209:00722
Karnack C85/AFHP303 5 8548_203_0002March 3 202211:00721
Dripping Springs School C614 11 61448_209_0614June 30 202211:00721 N
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675March 16 202211:00721 N
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675March 25 202211:00721 N
SETRPC 40 Sabine Pass C640/C1654 10 64048_245_0101May 26 202210:00721
SETRPC Port Arthur C628 10 62848_245_0628May 26 202211:00721 N
Kaufman C71/A304/X071 4 7148_257_0005May 28 202212:00721
Keller C17 4 1748_439_2003June 29 202210:00722
Grapevine Fairway C70/A301/X182 4 7048_439_3009June 21 202210:00721
Arlington Municipal Airport C61 4 6148_439_3011June 30 202209:00721
CAPCOG East Austin C1619 11 161948_453_1619May 26 202211:00721 N
Frisco C31/C680 4 3148_085_0005May 6 202212:00711
Denton Airport South C56/A163/X157 4 5648_121_0034May 14 202210:00711
Denton Airport South C56/A163/X157 4 5648_121_0034June 20 202210:00711
Pilot Point C1032 4 103248_121_1032March 3 202211:00711
Socorro Hueco C49/F312 6 4948_141_0057June 10 202210:00711
Galveston 99th St. C1034/A320/X183 12 103448_167_1034June 27 202214:00711
Houston Aldine C8/AF108/X150 12 848_201_0024May 16 202210:00712
Northwest Harris Co. C26/A110/X154 12 2648_201_0029May 11 202211:00712
Houston Bayland Park C53/A146 12 5348_201_0055May 26 202211:00711
Park Place C416 12 41648_201_0416June 26 202210:00711
HRM-3 Haden Road C603/A114 12 60348_201_0803May 26 202211:00711 N
Houston East C1/G316 12 148_201_1034May 26 202210:00712
Dripping Springs School C614 11 61448_209_0614June 4 202212:00711 N
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675March 26 202210:00711 N
CAPCOG San Marcos Staples Road C1675 11 167548_209_1675May 27 202211:00711 N
Granbury C73/C681 4 7348_221_0001June 30 202209:00711
Hamshire C64/C654 10 6448_245_0022May 26 202210:00711
Cleburne Airport C77/C682 4 7748_251_0003May 16 202210:00711
Liberty Sam Houston Library C1626 12 162648_291_1626March 26 202210:00711 N
Conroe Relocated C78/A321 12 7848_339_0078May 12 202211:00711
UH WG Jones Forest C698 12 69848_339_0698May 6 202211:00711 N
Corsicana Airport C1051 4 105148_349_1051May 26 202211:00711
Tyler Airport Relocated C82 5 8248_423_0007March 2 202210:00711
Tyler Airport Relocated C82 5 8248_423_0007March 26 202211:00711
Tyler Airport Relocated C82 5 8248_423_0007May 26 202210:00711
Eagle Mountain Lake C75 4 7548_439_0075March 3 202211:00711
Grapevine Fairway C70/A301/X182 4 7048_439_3009March 26 202212:00711
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.