Skip to content. | Skip to navigation

Personal tools

Navigation

Daily Maximum Eight-Hour Ozone Averages for September 2014

The table below lists the peak daily maximum eight-hour ozone concentrations measured in September 2014 in each community where the TCEQ measures ozone. Concentrations that are rated Moderate or higher are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.) All ozone measurements are in parts per billion.

Use the selection boxes below to customize this report. You may select a different month, a different year, a different report format, and whether or not to include time on the report. Click on the Generate Report button once you have made your selections.

Month:Year:Report Format: Include time:
Include time
Highlight with AQI colors
There are no eight-hour averages available for the month/year combination you selected.

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 - 0.059
51 - 100 Not Defined 0.06 - 0.075
101 - 150 0.125 - 0.164 0.076 - 0.095
151 - 200 0.165 - 0.204 0.096 - 0.115
201 - 300 0.205 - 0.404 0.116 - 0.374
301 - 400 0.405 - 0.504 Not Defined
401 - 500 0.505 - 0.604 Not Defined
500+ Not Defined Not Defined

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 beginning 1/1/2013, 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.