Today's Ozone Forecasts

Air Quality Index

Nine Texas communities are participating in the Ozone Forecast Program:  Austin, Beaumont-Port Arthur, Dallas-Fort Worth, Corpus Christi, Victoria, Houston-Galveston-Brazoria, San Antonio, El Paso-Juarez, and Tyler-Longview-Marshall. The table below provides information about whether Ozone is forecast to reach target levels in the affected area. Information about ozone forecast accuracy and other program statistics are available.

This table also lists the current peak one-hour and eight-hour concentrations and the corresponding Air Quality Index (AQI) rating for ozone for May 21, 2012. These ozone measurements are in parts per billion (ppb). The forecast is updated by 3:00 p.m. each day.



The following Ozone Forecast was updated at 1:14 pm CDT on May 20, 2012.

         
Metropolitan AreaOzone Forecast* for
May 21, 2012
May 21, 2012 as of 7:11 am CDT
Peak Ozone ConcentrationsOzone
AQI Rating
One-HourEight-Hour
Houston-Galveston-Brazoria ¹Yes-Orange43 ppb††**
Beaumont-Port Arthur No48 ppb††**
Dallas-Fort Worth No49 ppb††**
Tyler-Longview-Marshall No31 ppb††**
Austin No36 ppb††**
San Antonio No34 ppb††**
Corpus Christi No57 ppb††**
Victoria No32 ppb††**
El Paso-Juarez ¹No47 ppb††**
* Yes - Ozone is forecast to reach the target level.
   No - Ozone is not forecast to reach the target level.
See table below for terminology and target levels.
†† There are not enough one-hour samples available to create a valid eight-hour sample for this metropolitan area for May 21, 2012.
** There is no AQI associated with one-hour samples that are less than 0.125 ppm (125 ppb).
¹ These metropolitan areas have other, non-TCEQ operated monitors that contribute to the overall forecast assessment of the area. Data from these sites is not included in this table.
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.

Ozone Forecast Terminology and Targets

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.

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.