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Four Highest 24-Hour PM-2.5 Concentrations in 2017
as of February 20, 2017

Use this form to retrieve the four highest 24-hour PM-2.5 (Local Conditions) Acceptable concentration averages from data collected at TCEQ monitoring sites beginning January 1, 1998 through today. Although this is our most current data, it is not considered official until it has been certified by our technical staff. This information is updated hourly. All times shown are in Local Standard Time.

The table below lists the four highest daily maximum 24-hour PM-2.5 (Local Conditions) Acceptable concentrations measured in 2017 in each community where the TCEQ measures PM-2.5. Concentrations that are rated Moderate or higher are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.). All PM-2.5 measurements are in micrograms per cubic meter (local conditions). Sample times correspond to the beginning of the 24-hour average.

Use the selection boxes below to customize this report. You may select a different year or a different report format. If you want to cut and paste data from this web page into another application, such as a spreadsheet, select the comma-delimited format. Click on the Generate Report button once you have made your selections.

YearReport Format
Highlight with AQI colors
AreaMonitoring SitePOCHighestSecond HighestThird HighestFourth Highest
Amarillo Texas A&M C3203 N01/13/20179.101/14/20177.702/04/20177.201/12/20176.2
Lubbock 12th Street C10283 N02/04/201710.201/13/20179.301/11/20176.601/24/20175.8
Dallas-Fort Worth
Midlothian OFW C52/A1373 N02/11/201718.602/19/201717.602/10/201714.902/12/201712.8
Denton Airport South C56/A163/X1573 N02/19/201722.102/11/201718.602/10/201716.602/08/201715.0
Arlington Municipal Airport C613 N02/19/201717.702/11/201716.202/10/201713.701/07/201713.5
Kaufman C71/A304/X0713 N02/19/201716.502/11/201715.502/02/201715.401/01/201714.3
Haws Athletic Center C3103 N02/19/201714.902/11/201712.701/01/201711.401/12/201710.7
Corsicana Airport C10513 N01/13/201717.702/19/201715.301/01/201713.802/11/201713.7
Karnack C85/AFHP3033 N01/28/201732.702/01/201718.101/30/201716.302/11/201712.2
Texarkana New Boston C10313 N02/11/201716.302/19/201713.401/14/201712.202/08/201712.0
El Paso-Juarez
El Paso UTEP C12/A125/X1513 N02/02/201716.401/08/201715.502/18/201714.502/03/201714.1
Socorro Hueco C49/F3123 N02/12/201717.602/11/201714.701/13/201712.701/09/201712.4
Odessa Gonzales C1014 3 N02/04/201710.702/05/201710.402/12/20179.502/11/20178.7
Waco Mazanec C10373 N01/13/201715.502/11/201710.801/12/201710.302/19/201710.1
Beaumont-Port Arthur
Port Arthur Memorial School C303/C6893 N01/21/201718.602/08/201715.702/12/201714.702/13/201712.4
SETRPC Mauriceville 42 C642/C311/C6653 N02/07/201713.902/08/201713.002/13/201712.801/21/201712.5
Austin Northwest C3/A3223 N02/11/201717.902/19/201716.302/04/201713.902/10/201713.2
Audubon C383 N02/11/201717.402/19/201715.202/10/201712.402/04/201710.5
Zavala C3263 N01/01/201723.402/11/201717.502/19/201716.802/04/201714.1
Fayette County C6013 N02/19/201714.202/13/201712.202/10/201711.202/11/201710.7
Houston East C1/G3163 N01/01/201718.602/09/201714.902/19/201713.702/08/201712.6
Houston Aldine C8/AF108/X150 3 N02/19/201713.202/02/201712.902/09/201712.202/12/201711.3
Hou.DeerPrk2 C35/235/1001/AFH139FP2393 N02/09/201717.102/19/201712.902/08/201712.802/13/201711.8
Seabrook Friendship Park C453 N02/09/201715.801/21/201713.402/08/201712.702/19/201711.4
Conroe Relocated C78/A3213 N01/01/201718.202/13/201713.402/12/201713.202/19/201712.9
Clinton C403/C304/AH113 3 N01/01/201716.202/09/201714.902/19/201713.802/08/201713.8
Galveston 99th St. C1034/A320/X1833 N01/21/201715.802/08/201713.902/19/201712.602/09/201712.2
San Antonio
San Antonio Northwest C233 N01/01/201742.702/19/201719.702/11/201716.902/05/201715.7
Calaveras Lake C593 N01/01/201722.202/19/201719.702/11/201714.802/04/201713.7
Selma C3013 N01/01/201725.102/19/201717.502/11/201716.902/04/201713.5
Heritage Middle School C6223 N01/01/201725.302/19/201718.802/11/201715.402/04/201713.7
Palo Alto C6763 N01/01/201765.002/19/201718.602/11/201716.602/05/201715.2
Old Highway 90 C677/A3193 N01/01/201749.902/05/201719.502/01/201719.501/08/201719.5
Corpus Christi-Victoria
National Seashore C3143 N02/03/201718.202/08/201716.002/19/201715.501/21/201714.5
Dona Park C635/AF199/F2993 N01/01/201718.102/03/201717.502/19/201717.002/18/201713.8
Lower Rio Grande Valley
Mission C43/AP1433 N02/19/201721.002/08/201721.002/18/201718.802/02/201718.0
World Trade Bridge C3133 N02/19/201721.602/11/201717.802/02/201717.002/10/201716.8
Eagle Pass C319/C6553 N01/01/201725.402/19/201719.102/11/201717.902/10/201714.9
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

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 24hr PM-2.5
in µg/m³ LC
0 - 50 0 - 12.0
51 - 100 12.1 - 35.4
101 - 150 35.5 - 55.4
151 - 200 55.5 - 150.4
201 - 300 150.5 - 250.4
301 - 400 250.5 - 350.4
401 - 500 350.5 - 500.4
500+ 500.5 - 999.9

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.