Eight-Hour Ozone High Value Days for 2024
as of May 19
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.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.
| 2024 Sorted by Maximum Value | |||||||
|---|---|---|---|---|---|---|---|
| Location | Region | CAMS | AQS | Date | Time | Value | POC |
| Meyer Park C561 | 12 | 561 | 48_201_0561 | May 15 2024 | 10:00 | 103 | 1 N |
| Mercer Arboretum C557 | 12 | 557 | 48_201_0557 | May 18 2024 | 11:00 | 100 | 1 N |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | May 15 2024 | 11:00 | 98 | 2 |
| Houston East C1/G316 | 12 | 1 | 48_201_1034 | May 15 2024 | 09:00 | 98 | 2 |
| Northwest Harris Co. C26/A110/X154 | 12 | 26 | 48_201_0029 | May 15 2024 | 11:00 | 96 | 2 |
| Mercer Arboretum C557 | 12 | 557 | 48_201_0557 | May 15 2024 | 09:00 | 95 | 1 N |
| Houston North Wayside C405/C1033 | 12 | 405 | 48_201_0046 | May 15 2024 | 11:00 | 94 | 1 |
| Atascocita C560 | 12 | 560 | 48_201_0560 | May 18 2024 | 10:00 | 94 | 1 N |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | May 15 2024 | 10:00 | 92 | 1 |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | May 18 2024 | 11:00 | 91 | 2 |
| CAPCOG Round Rock Brushy Creek W C1620 | 11 | 1620 | 48_491_1620 | May 8 2024 | 12:00 | 87 | 1 N |
| Heritage Middle School C622 | 13 | 622 | 48_029_0622 | May 14 2024 | 11:00 | 86 | 1 N |
| Atascocita C560 | 12 | 560 | 48_201_0560 | May 15 2024 | 10:00 | 86 | 1 N |
| Lynchburg Ferry C1015/A165 | 12 | 1015 | 48_201_1015 | May 15 2024 | 10:00 | 86 | 1 |
| Houston Harvard Street C417 | 12 | 417 | 48_201_0417 | May 15 2024 | 08:00 | 85 | 1 |
| Lang C408 | 12 | 408 | 48_201_0047 | May 15 2024 | 10:00 | 83 | 2 |
| Huffman Wolf Road C563 | 12 | 563 | 48_201_0563 | May 15 2024 | 09:00 | 83 | 1 N |
| Nederland 17th Street C1035 | 10 | 1035 | 48_245_1035 | May 15 2024 | 10:00 | 83 | 1 |
| Channelview C15/AH115 | 12 | 15 | 48_201_0026 | May 15 2024 | 10:00 | 82 | 3 |
| Crosby Library C553 | 12 | 553 | 48_201_0553 | May 15 2024 | 08:00 | 82 | 1 N |
| Clinton C403/C304/AH113 | 12 | 403 | 48_201_1035 | May 15 2024 | 11:00 | 81 | 3 |
| Hou.DeerPrk2 C35/235/1001/AFH139FP239 | 12 | 35 | 48_201_1039 | May 15 2024 | 10:00 | 81 | 1 |
| Park Place C416 | 12 | 416 | 48_201_0416 | May 15 2024 | 11:00 | 80 | 1 |
| Government Canyon C1610 | 13 | 1610 | 48_029_1610 | May 9 2024 | 11:00 | 79 | 1 N |
| Beaumont-Downtown C2/A112/C2002 | 10 | 2 | 48_245_0009 | May 15 2024 | 10:00 | 79 | 2 |
| Laredo College C44 | 16 | 44 | 48_479_0016 | May 18 2024 | 10:00 | 79 | 1 N |
| West Houston C554 | 12 | 554 | 48_201_0554 | May 15 2024 | 10:00 | 78 | 1 N |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | May 18 2024 | 13:00 | 78 | 1 |
| UH Moody Tower C695 | 12 | 695 | 48_201_0695 | May 15 2024 | 11:00 | 77 | 1 N |
| Government Canyon C1610 | 13 | 1610 | 48_029_1610 | May 14 2024 | 12:00 | 76 | 1 N |
| Pilot Point C1032 | 4 | 1032 | 48_121_1032 | May 15 2024 | 10:00 | 76 | 1 |
| Texas City 34th St. C620 | 12 | 620 | 48_167_0056 | April 4 2024 | 11:00 | 76 | 1 N |
| Sheldon C551 | 12 | 551 | 48_201_0551 | May 15 2024 | 10:00 | 76 | 1 N |
| Dripping Springs School C614 | 11 | 614 | 48_209_0614 | May 15 2024 | 09:00 | 76 | 1 N |
| West Orange C9/A141 | 10 | 9 | 48_361_1001 | May 15 2024 | 12:00 | 76 | 2 |
| Calaveras Lake C59 | 13 | 59 | 48_029_0059 | May 14 2024 | 11:00 | 75 | 1 |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | May 15 2024 | 12:00 | 75 | 1 |
| Houston Bayland Park C53/A146 | 12 | 53 | 48_201_0055 | May 15 2024 | 11:00 | 75 | 1 |
| Bunker Hill Village C562 | 12 | 562 | 48_201_0562 | May 15 2024 | 10:00 | 75 | 1 N |
| Huffman Wolf Road C563 | 12 | 563 | 48_201_0563 | May 18 2024 | 10:00 | 75 | 1 N |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | May 14 2024 | 13:00 | 74 | 1 |
| Channelview C15/AH115 | 12 | 15 | 48_201_0026 | May 18 2024 | 10:00 | 74 | 3 |
| La Porte Sylvan Beach C556 | 12 | 556 | 48_201_0556 | May 15 2024 | 10:00 | 74 | 1 N |
| Mercer Arboretum C557 | 12 | 557 | 48_201_0557 | April 12 2024 | 10:00 | 74 | 1 N |
| SETRPC 43 Jefferson Co Airport C643 | 10 | 643 | 48_245_0102 | May 15 2024 | 10:00 | 74 | 1 |
| Corsicana Airport C1051 | 4 | 1051 | 48_349_1051 | May 14 2024 | 11:00 | 74 | 1 |
| San Antonio Northwest C23 | 13 | 23 | 48_029_0032 | May 14 2024 | 12:00 | 73 | 2 |
| Elm Creek Elementary C501 | 13 | 501 | 48_029_0501 | May 14 2024 | 12:00 | 73 | 1 N |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | April 12 2024 | 10:00 | 73 | 2 |
| Sheldon C551 | 12 | 551 | 48_201_0551 | May 18 2024 | 10:00 | 73 | 1 N |
| Port Arthur West C28/A128/A228 | 10 | 28 | 48_245_0011 | May 15 2024 | 12:00 | 73 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 5 2024 | 10:00 | 73 | 1 |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | April 12 2024 | 12:00 | 73 | 1 N |
| Denton Airport South C56/A163/X157 | 4 | 56 | 48_121_0034 | May 18 2024 | 11:00 | 72 | 1 |
| Northwest Harris Co. C26/A110/X154 | 12 | 26 | 48_201_0029 | April 30 2024 | 11:00 | 72 | 2 |
| Meyer Park C561 | 12 | 561 | 48_201_0561 | April 30 2024 | 10:00 | 72 | 1 N |
| Dripping Springs School C614 | 11 | 614 | 48_209_0614 | May 14 2024 | 12:00 | 72 | 1 N |
| Hamshire C64/C654 | 10 | 64 | 48_245_0022 | May 15 2024 | 10:00 | 72 | 1 |
| CAPCOG Elgin C1613 | 11 | 1613 | 48_021_1613 | May 8 2024 | 11:00 | 71 | 1 N |
| Killeen Skylark Field C1047 | 9 | 1047 | 48_027_1047 | May 15 2024 | 09:00 | 71 | 1 |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | April 4 2024 | 12:00 | 71 | 1 |
| Baytown Garth C1017 | 12 | 1017 | 48_201_1017 | May 15 2024 | 10:00 | 71 | 1 |
| Kaufman C71/A304/X071 | 4 | 71 | 48_257_0005 | May 14 2024 | 11:00 | 71 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 12 2024 | 12:00 | 71 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 13 2024 | 10:00 | 71 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 30 2024 | 10:00 | 71 | 1 |
| 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.