Eight-Hour Ozone High Value Days for 2017
as of August 19
The table below lists the daily maximum eight-hour ozone concentrations measured which meet or exceed 71 parts per billion in 2017 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.Use the selection boxes below to customize this report. You may select a different year, a different sorting order, or a different report format. Click on the Generate Report button once you have made your selections.
| 2017 Sorted by Maximum Value | |||||||
|---|---|---|---|---|---|---|---|
| Location | Region | CAMS | AQS | Date | Time | Value | POC |
| Camp Bullis C58 | 13 | 58 | 48_029_0052 | June 8 2017 | 11:00 | 89 | 1 |
| Manvel Croix Park C84 | 12 | 84 | 48_039_1004 | June 8 2017 | 10:00 | 87 | 1 |
| Bulverde Elementary C503 | 13 | 503 | 48_091_0503 | June 8 2017 | 11:00 | 87 | 1 N |
| Crosby Library C553 | 12 | 553 | 48_201_0553 | May 6 2017 | 11:00 | 84 | 1 N |
| Baytown Garth C1017 | 12 | 1017 | 48_201_1017 | May 6 2017 | 10:00 | 84 | 1 |
| Cleburne Airport C77/C682 | 4 | 77 | 48_251_0003 | June 7 2017 | 10:00 | 84 | 1 |
| Crosby Library C553 | 12 | 553 | 48_201_0553 | April 24 2017 | 10:00 | 83 | 1 N |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | May 7 2017 | 10:00 | 83 | 1 N |
| Grapevine Fairway C70/A301/X182 | 4 | 70 | 48_439_3009 | August 4 2017 | 10:00 | 83 | 1 |
| U of H-Sugarland C696 | 12 | 696 | 48_157_0696 | June 8 2017 | 11:00 | 82 | 1 N |
| Wallisville Road C617 | 12 | 617 | 48_201_0617 | May 6 2017 | 10:00 | 82 | 1 N |
| City of Garden Ridge C505 | 13 | 505 | 48_091_0505 | June 8 2017 | 11:00 | 81 | 1 N |
| UH Moody Tower C695 | 12 | 695 | 48_201_0695 | May 6 2017 | 11:00 | 81 | 1 N |
| HRM-3 Haden Road C603/A114 | 12 | 603 | 48_201_0803 | May 6 2017 | 10:00 | 81 | 1 N |
| Houston East C1/G316 | 12 | 1 | 48_201_1034 | May 6 2017 | 10:00 | 81 | 2 |
| Hou.DeerPrk2 C35/235/1001/AFH139FP239 | 12 | 35 | 48_201_1039 | May 6 2017 | 10:00 | 81 | 1 |
| Granbury C73/C681 | 4 | 73 | 48_221_0001 | July 31 2017 | 13:00 | 81 | 1 |
| Cleburne Airport C77/C682 | 4 | 77 | 48_251_0003 | July 31 2017 | 12:00 | 81 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 7 2017 | 11:00 | 81 | 1 |
| San Antonio Northwest C23 | 13 | 23 | 48_029_0032 | June 8 2017 | 11:00 | 80 | 2 |
| Manvel Croix Park C84 | 12 | 84 | 48_039_1004 | May 6 2017 | 11:00 | 80 | 1 |
| Dallas Hinton St. C401/C60/AH161 | 4 | 401 | 48_113_0069 | May 6 2017 | 11:00 | 80 | 3 |
| Dallas North No.2 C63/C679 | 4 | 63 | 48_113_0075 | May 6 2017 | 11:00 | 80 | 1 |
| Denton Airport South C56/A163/X157 | 4 | 56 | 48_121_0034 | June 8 2017 | 11:00 | 80 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 24 2017 | 12:00 | 80 | 1 |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | April 24 2017 | 11:00 | 80 | 1 N |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | May 15 2017 | 10:00 | 79 | 1 |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | April 7 2017 | 12:00 | 79 | 1 N |
| Ft. Worth Northwest C13/AH302 | 4 | 13 | 48_439_1002 | May 30 2017 | 10:00 | 79 | 2 |
| Keller C17 | 4 | 17 | 48_439_2003 | August 4 2017 | 11:00 | 79 | 2 |
| Dallas Hinton St. C401/C60/AH161 | 4 | 401 | 48_113_0069 | August 4 2017 | 11:00 | 78 | 3 |
| Channelview C15/AH115 | 12 | 15 | 48_201_0026 | May 6 2017 | 12:00 | 78 | 3 |
| Baytown Garth C1017 | 12 | 1017 | 48_201_1017 | April 7 2017 | 11:00 | 78 | 1 |
| Clinton C403/C304/AH113 | 12 | 403 | 48_201_1035 | May 6 2017 | 11:00 | 78 | 3 |
| Seabrook Friendship Park C45 | 12 | 45 | 48_201_1050 | August 4 2017 | 10:00 | 78 | 1 |
| UH West Liberty C699 | 12 | 699 | 48_291_0699 | April 7 2017 | 11:00 | 78 | 1 N |
| Grapevine Fairway C70/A301/X182 | 4 | 70 | 48_439_3009 | June 8 2017 | 11:00 | 78 | 1 |
| Elm Creek Elementary C501 | 13 | 501 | 48_029_0501 | May 13 2017 | 12:00 | 77 | 1 N |
| Heritage Middle School C622 | 13 | 622 | 48_029_0622 | June 8 2017 | 11:00 | 77 | 1 N |
| Manvel Croix Park C84 | 12 | 84 | 48_039_1004 | May 23 2017 | 11:00 | 77 | 1 |
| Dallas North No.2 C63/C679 | 4 | 63 | 48_113_0075 | August 4 2017 | 10:00 | 77 | 1 |
| Midlothian OFW C52/A137 | 4 | 52 | 48_139_0016 | June 7 2017 | 10:00 | 77 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | May 7 2017 | 10:00 | 77 | 1 |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | May 15 2017 | 11:00 | 77 | 1 N |
| Ft. Worth Northwest C13/AH302 | 4 | 13 | 48_439_1002 | August 4 2017 | 11:00 | 77 | 2 |
| Pilot Point C1032 | 4 | 1032 | 48_121_1032 | June 8 2017 | 11:00 | 76 | 1 |
| Texas City 34th St. C620 | 12 | 620 | 48_167_0056 | August 4 2017 | 10:00 | 76 | 1 N |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | May 12 2017 | 11:00 | 76 | 1 |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | May 6 2017 | 11:00 | 76 | 2 |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | May 14 2017 | 10:00 | 76 | 2 |
| Northwest Harris Co. C26/A110/X154 | 12 | 26 | 48_201_0029 | June 9 2017 | 11:00 | 76 | 2 |
| Houston North Wayside C405 | 12 | 405 | 48_201_0046 | May 6 2017 | 11:00 | 76 | 1 |
| Cleburne Airport C77/C682 | 4 | 77 | 48_251_0003 | August 3 2017 | 11:00 | 76 | 1 |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | May 2 2017 | 10:00 | 76 | 1 N |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | June 9 2017 | 10:00 | 76 | 1 N |
| Eagle Mountain Lake C75 | 4 | 75 | 48_439_0075 | August 4 2017 | 11:00 | 76 | 1 |
| Temple Georgia C1045 | 9 | 1045 | 48_027_1045 | May 6 2017 | 10:00 | 75 | 1 |
| San Antonio Northwest C23 | 13 | 23 | 48_029_0032 | August 1 2017 | 10:00 | 75 | 2 |
| Fair Oaks Ranch C502 | 13 | 502 | 48_029_0502 | June 8 2017 | 11:00 | 75 | 1 N |
| Ivanhoe C414 | 6 | 414 | 48_141_0029 | June 27 2017 | 12:00 | 75 | 1 |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | June 6 2017 | 10:00 | 75 | 2 |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | June 27 2017 | 10:00 | 75 | 2 |
| Skyline Park C72 | 6 | 72 | 48_141_0058 | June 27 2017 | 11:00 | 75 | 1 |
| Wallisville Road C617 | 12 | 617 | 48_201_0617 | April 7 2017 | 10:00 | 75 | 1 N |
| Baytown Garth C1017 | 12 | 1017 | 48_201_1017 | April 24 2017 | 10:00 | 75 | 1 |
| Cleburne Airport C77/C682 | 4 | 77 | 48_251_0003 | July 29 2017 | 15:00 | 75 | 1 |
| UH West Liberty C699 | 12 | 699 | 48_291_0699 | April 24 2017 | 11:00 | 75 | 1 N |
| Eagle Mountain Lake C75 | 4 | 75 | 48_439_0075 | May 30 2017 | 11:00 | 75 | 1 |
| Keller C17 | 4 | 17 | 48_439_2003 | May 6 2017 | 12:00 | 75 | 2 |
| Keller C17 | 4 | 17 | 48_439_2003 | June 23 2017 | 12:00 | 75 | 2 |
| Arlington Municipal Airport C61 | 4 | 61 | 48_439_3011 | August 3 2017 | 11:00 | 75 | 1 |
| CAPCOG Lake Georgetown C690 | 11 | 690 | 48_491_0690 | June 8 2017 | 11:00 | 75 | 1 N |
| San Antonio Northwest C23 | 13 | 23 | 48_029_0032 | May 7 2017 | 10:00 | 74 | 2 |
| Lockhart C1604 | 11 | 1604 | 48_055_1604 | June 7 2017 | 10:00 | 74 | 1 N |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | July 28 2017 | 11:00 | 74 | 2 |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | August 17 2017 | 11:00 | 74 | 2 |
| Chamizal C41/AH126 | 6 | 41 | 48_141_0044 | June 4 2017 | 10:00 | 74 | 1 |
| Chamizal C41/AH126 | 6 | 41 | 48_141_0044 | June 27 2017 | 10:00 | 74 | 1 |
| U of H-Sugarland C696 | 12 | 696 | 48_157_0696 | May 6 2017 | 11:00 | 74 | 1 N |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | May 6 2017 | 13:00 | 74 | 1 |
| Northwest Harris Co. C26/A110/X154 | 12 | 26 | 48_201_0029 | May 14 2017 | 11:00 | 74 | 2 |
| Houston Croquet C409 | 12 | 409 | 48_201_0051 | May 6 2017 | 11:00 | 74 | 2 |
| Houston Croquet C409 | 12 | 409 | 48_201_0051 | June 8 2017 | 10:00 | 74 | 2 |
| Houston Bayland Park C53/A146 | 12 | 53 | 48_201_0055 | May 6 2017 | 11:00 | 74 | 1 |
| Clear Brook High School C570 | 12 | 570 | 48_201_0570 | May 6 2017 | 11:00 | 74 | 1 N |
| Wallisville Road C617 | 12 | 617 | 48_201_0617 | April 24 2017 | 10:00 | 74 | 1 N |
| Waco Mazanec C1037 | 9 | 1037 | 48_309_1037 | May 6 2017 | 10:00 | 74 | 1 |
| Parker County C76 | 4 | 76 | 48_367_0081 | May 30 2017 | 11:00 | 74 | 1 |
| Ft. Worth Northwest C13/AH302 | 4 | 13 | 48_439_1002 | May 13 2017 | 12:00 | 74 | 2 |
| San Antonio Northwest C23 | 13 | 23 | 48_029_0032 | August 4 2017 | 11:00 | 73 | 2 |
| Frisco C31/C680 | 4 | 31 | 48_085_0005 | May 6 2017 | 12:00 | 73 | 1 |
| Frisco C31/C680 | 4 | 31 | 48_085_0005 | August 10 2017 | 12:00 | 73 | 1 |
| Dallas North No.2 C63/C679 | 4 | 63 | 48_113_0075 | August 10 2017 | 11:00 | 73 | 1 |
| Denton Airport South C56/A163/X157 | 4 | 56 | 48_121_0034 | May 7 2017 | 10:00 | 73 | 1 |
| Denton Airport South C56/A163/X157 | 4 | 56 | 48_121_0034 | May 31 2017 | 10:00 | 73 | 1 |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | June 4 2017 | 10:00 | 73 | 2 |
| Texas City 34th St. C620 | 12 | 620 | 48_167_0056 | May 6 2017 | 11:00 | 73 | 1 N |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | May 7 2017 | 03:00 | 73 | 1 |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | June 8 2017 | 11:00 | 73 | 1 |
| Houston Bayland Park C53/A146 | 12 | 53 | 48_201_0055 | June 8 2017 | 10:00 | 73 | 1 |
| Park Place C416 | 12 | 416 | 48_201_0416 | May 6 2017 | 10:00 | 73 | 1 |
| Seabrook Friendship Park C45 | 12 | 45 | 48_201_1050 | May 6 2017 | 11:00 | 73 | 1 |
| Beaumont-Downtown C2/A112/C2002 | 10 | 2 | 48_245_0009 | May 14 2017 | 10:00 | 73 | 2 |
| Cleburne Airport C77/C682 | 4 | 77 | 48_251_0003 | May 13 2017 | 11:00 | 73 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | May 2 2017 | 10:00 | 73 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | June 9 2017 | 10:00 | 73 | 1 |
| Grapevine Fairway C70/A301/X182 | 4 | 70 | 48_439_3009 | June 23 2017 | 12:00 | 73 | 1 |
| Audubon C38 | 11 | 38 | 48_453_0020 | June 8 2017 | 10:00 | 73 | 1 |
| CAPCOG Lake Georgetown C690 | 11 | 690 | 48_491_0690 | May 6 2017 | 11:00 | 73 | 1 N |
| Temple Georgia C1045 | 9 | 1045 | 48_027_1045 | May 7 2017 | 11:00 | 72 | 1 |
| Temple Georgia C1045 | 9 | 1045 | 48_027_1045 | June 7 2017 | 12:00 | 72 | 1 |
| Camp Bullis C58 | 13 | 58 | 48_029_0052 | May 7 2017 | 11:00 | 72 | 1 |
| Camp Bullis C58 | 13 | 58 | 48_029_0052 | August 1 2017 | 10:00 | 72 | 1 |
| Camp Bullis C58 | 13 | 58 | 48_029_0052 | August 4 2017 | 11:00 | 72 | 1 |
| Frisco C31/C680 | 4 | 31 | 48_085_0005 | June 8 2017 | 10:00 | 72 | 1 |
| Dallas North No.2 C63/C679 | 4 | 63 | 48_113_0075 | June 8 2017 | 11:00 | 72 | 1 |
| Denton Airport South C56/A163/X157 | 4 | 56 | 48_121_0034 | July 24 2017 | 12:00 | 72 | 1 |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | June 7 2017 | 10:00 | 72 | 2 |
| Chamizal C41/AH126 | 6 | 41 | 48_141_0044 | May 20 2017 | 12:00 | 72 | 1 |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | April 7 2017 | 10:00 | 72 | 1 |
| Houston Westhollow C410 | 12 | 410 | 48_201_0066 | June 8 2017 | 10:00 | 72 | 1 |
| Dripping Springs School C614 | 11 | 614 | 48_209_0614 | August 1 2017 | 11:00 | 72 | 1 N |
| Rockwall Heath C69 | 4 | 69 | 48_397_0001 | May 6 2017 | 11:00 | 72 | 1 |
| Ft. Worth Northwest C13/AH302 | 4 | 13 | 48_439_1002 | May 6 2017 | 11:00 | 72 | 2 |
| Keller C17 | 4 | 17 | 48_439_2003 | May 30 2017 | 11:00 | 72 | 2 |
| Keller C17 | 4 | 17 | 48_439_2003 | June 8 2017 | 11:00 | 72 | 2 |
| Killeen Skylark Field C1047 | 9 | 1047 | 48_027_1047 | April 7 2017 | 11:00 | 71 | 1 |
| Danciger C618 | 12 | 618 | 48_039_0618 | July 31 2017 | 11:00 | 71 | 1 N |
| Frisco C31/C680 | 4 | 31 | 48_085_0005 | June 23 2017 | 11:00 | 71 | 1 |
| Frisco C31/C680 | 4 | 31 | 48_085_0005 | August 4 2017 | 10:00 | 71 | 1 |
| Denton Airport South C56/A163/X157 | 4 | 56 | 48_121_0034 | May 6 2017 | 10:00 | 71 | 1 |
| Denton Airport South C56/A163/X157 | 4 | 56 | 48_121_0034 | August 4 2017 | 11:00 | 71 | 1 |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | June 5 2017 | 10:00 | 71 | 2 |
| El Paso UTEP C12/A125/X151 | 6 | 12 | 48_141_0037 | July 10 2017 | 10:00 | 71 | 2 |
| Chamizal C41/AH126 | 6 | 41 | 48_141_0044 | July 10 2017 | 09:00 | 71 | 1 |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | May 7 2017 | 09:00 | 71 | 2 |
| Northwest Harris Co. C26/A110/X154 | 12 | 26 | 48_201_0029 | May 7 2017 | 11:00 | 71 | 2 |
| Houston North Wayside C405 | 12 | 405 | 48_201_0046 | May 14 2017 | 10:00 | 71 | 1 |
| Houston Westhollow C410 | 12 | 410 | 48_201_0066 | May 6 2017 | 11:00 | 71 | 1 |
| UH Moody Tower C695 | 12 | 695 | 48_201_0695 | June 8 2017 | 10:00 | 71 | 1 N |
| HRM-3 Haden Road C603/A114 | 12 | 603 | 48_201_0803 | April 7 2017 | 10:00 | 71 | 1 N |
| Granbury C73/C681 | 4 | 73 | 48_221_0001 | June 21 2017 | 10:00 | 71 | 1 |
| Eagle Mountain Lake C75 | 4 | 75 | 48_439_0075 | June 8 2017 | 11:00 | 71 | 1 |
| Grapevine Fairway C70/A301/X182 | 4 | 70 | 48_439_3009 | August 10 2017 | 11:00 | 71 | 1 |
| Arlington Municipal Airport C61 | 4 | 61 | 48_439_3011 | May 13 2017 | 11:00 | 71 | 1 |
| Arlington Municipal Airport C61 | 4 | 61 | 48_439_3011 | June 7 2017 | 10:00 | 71 | 1 |
| Austin Northwest C3/A322 | 11 | 3 | 48_453_0014 | May 6 2017 | 10:00 | 71 | 2 |
| Austin Northwest C3/A322 | 11 | 3 | 48_453_0014 | June 8 2017 | 11:00 | 71 | 2 |
| 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
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.