Eight-Hour Ozone High Value Days for 2019
as of April 24
The table below lists the daily maximum eight-hour ozone concentrations measured which meet or exceed 71 parts per billion in 2019 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.
| 2019 Sorted by Maximum Value | |||||||
|---|---|---|---|---|---|---|---|
| Location | Region | CAMS | AQS | Date | Time | Value | POC |
| Tyler Airport Relocated C82 | 5 | 82 | 48_423_0007 | April 9 2019 | 11:00 | 80 | 1 |
| Galveston 99th St. C1034/A320/X183 | 12 | 1034 | 48_167_1034 | March 22 2019 | 13:00 | 79 | 1 |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | March 22 2019 | 11:00 | 78 | 1 |
| UH Moody Tower C695 | 12 | 695 | 48_201_0695 | March 20 2019 | 11:00 | 77 | 1 N |
| Clinton C403/C304/AH113 | 12 | 403 | 48_201_1035 | March 20 2019 | 10:00 | 77 | 3 |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | March 22 2019 | 11:00 | 77 | 1 N |
| Hou.DeerPrk2 C35/235/1001/AFH139FP239 | 12 | 35 | 48_201_1039 | April 9 2019 | 12:00 | 76 | 1 |
| UH Moody Tower C695 | 12 | 695 | 48_201_0695 | April 9 2019 | 11:00 | 75 | 1 N |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 21 2019 | 10:00 | 75 | 1 |
| Longview C19/A127/C644 | 5 | 19 | 48_183_0001 | April 9 2019 | 11:00 | 74 | 2 |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | April 9 2019 | 11:00 | 74 | 2 |
| Wallisville Road C617 | 12 | 617 | 48_201_0617 | April 9 2019 | 11:00 | 74 | 1 N |
| SETRPC 43 Jefferson Co Airport C643 | 10 | 643 | 48_245_0102 | March 22 2019 | 11:00 | 74 | 1 |
| Oyster Creek C1607 | 12 | 1607 | 48_039_1607 | March 22 2019 | 10:00 | 73 | 1 N |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | March 27 2019 | 10:00 | 73 | 2 |
| Channelview C15/AH115 | 12 | 15 | 48_201_0026 | April 9 2019 | 11:00 | 73 | 3 |
| Baytown Garth C1017 | 12 | 1017 | 48_201_1017 | April 9 2019 | 11:00 | 73 | 1 |
| Hou.DeerPrk2 C35/235/1001/AFH139FP239 | 12 | 35 | 48_201_1039 | March 20 2019 | 12:00 | 73 | 1 |
| Killeen Skylark Field C1047 | 9 | 1047 | 48_027_1047 | April 9 2019 | 11:00 | 72 | 1 |
| Texas City 34th St. C620 | 12 | 620 | 48_167_0056 | April 9 2019 | 10:00 | 72 | 1 N |
| Northwest Harris Co. C26/A110/X154 | 12 | 26 | 48_201_0029 | March 22 2019 | 10:00 | 72 | 2 |
| Park Place C416 | 12 | 416 | 48_201_0416 | April 9 2019 | 11:00 | 72 | 1 |
| HRM-3 Haden Road C603/A114 | 12 | 603 | 48_201_0803 | March 20 2019 | 10:00 | 72 | 1 N |
| Conroe Relocated C78/A321 | 12 | 78 | 48_339_0078 | April 15 2019 | 11:00 | 72 | 1 |
| Manvel Croix Park C84 | 12 | 84 | 48_039_1004 | March 20 2019 | 11:00 | 71 | 1 |
| Texas City 34th St. C620 | 12 | 620 | 48_167_0056 | March 21 2019 | 11:00 | 71 | 1 N |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | March 20 2019 | 11:00 | 71 | 2 |
| Houston Aldine C8/AF108/X150 | 12 | 8 | 48_201_0024 | March 22 2019 | 10:00 | 71 | 2 |
| HRM-3 Haden Road C603/A114 | 12 | 603 | 48_201_0803 | April 9 2019 | 11:00 | 71 | 1 N |
| UH WG Jones Forest C698 | 12 | 698 | 48_339_0698 | April 9 2019 | 11:00 | 71 | 1 N |
| 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.