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Four Highest 24-Hour PM-2.5 Concentrations in 2021
as of September 20, 2021

Use this form to retrieve the four highest 24-hour PM-2.5 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 concentrations measured in 2021 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 (midnight to midnight).

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 C320208/02/202126.409/11/202123.509/12/202119.708/06/202116.4
Lubbock 12th Street C1028108/02/202127.107/13/202121.208/03/202121.102/19/202119.2
Dallas-Fort Worth
Ft. Worth Northwest C13/AH302 307/04/202128.308/03/202127.207/05/202125.708/02/202124.9
Midlothian OFW C52/A1373 N08/04/202118.608/05/202117.201/12/202116.709/05/202116.4
Denton Airport South C56/A163/X157107/25/202122.007/24/202121.807/21/202119.801/30/202118.0
Kaufman C71/A304/X0713 N09/05/202122.504/09/202120.703/27/202120.007/25/202118.4
Haws Athletic Center C310208/03/202129.608/04/202124.907/24/202123.608/02/202123.5
Dallas Hinton St. C401/C60/AH161 408/05/202127.007/24/202121.907/21/202121.507/25/202121.4
Corsicana Airport C10513 N09/05/202123.906/19/202121.307/24/202120.904/09/202120.6
Ft Worth California Parkway North C1053208/03/202127.308/04/202124.807/04/202124.608/05/202122.8
Ft Worth California Parkway North C1053308/03/202127.807/04/202124.708/04/202124.408/05/202124.0
Karnack C85/AFHP303208/06/202123.707/25/202123.508/04/202123.008/05/202122.1
Karnack C85/AFHP3033 N04/03/202140.403/19/202137.404/02/202136.005/03/202116.8
Texarkana New Boston C1031208/03/202127.307/04/202125.507/25/202125.408/06/202123.7
El Paso-Juarez
El Paso UTEP C12/A125/X151/G1253 N03/16/202154.809/07/202131.406/21/202129.006/02/202126.4
Ascarate Park SE C37/A332/A172/X1593 N03/16/202153.406/21/202149.405/22/202128.606/20/202128.3
Chamizal C41/AH126 606/02/202122.606/21/202122.302/16/202121.803/16/202119.0
Socorro Hueco C49/F3123 N03/16/202153.706/21/202133.506/22/202126.606/23/202125.6
BRAVO Big Bend C67/C316/C656/C691103/23/202136.103/13/202133.603/22/202123.003/14/202120.7
Odessa Gonzales C1014 103/16/202130.408/03/202124.308/04/202120.603/17/202120.3
Waco Mazanec C10373 N04/09/202124.401/16/202122.804/02/202121.905/03/202121.6
Temple Georgia C1045101/16/202132.004/09/202124.707/24/202122.909/04/202121.6
Bryan Finfeather Road101/16/202127.609/05/202123.708/05/202121.703/27/202121.6
Beaumont-Port Arthur
Hamshire C64/C654209/05/202125.509/04/202123.501/17/202120.007/11/202119.7
Port Arthur Memorial School C303/C689409/05/202127.609/04/202123.507/11/202122.607/12/202118.7
SETRPC Port Arthur C6281 N01/03/202134.209/05/202131.609/04/202128.207/11/202124.4
SETRPC Mauriceville 42 C642/C311/C665101/17/202123.409/05/202123.309/04/202121.105/03/202120.7
Austin North Hills Drive C3/A322104/09/202127.509/04/202126.407/24/202123.803/27/202123.3
Austin Webberville Road AF171304/09/202128.909/04/202126.003/27/202125.007/24/202124.0
Austin North Interstate 35 C1068204/09/202128.209/04/202127.101/17/202124.607/24/202123.5
Jarrell FM 487 C10941 N04/09/202126.501/16/202123.907/24/202123.506/21/202120.5
Houston East C1/G316101/17/202147.409/05/202125.909/04/202125.801/16/202123.6
Houston Aldine C8/AF108/X150 401/17/202134.101/16/202127.409/05/202123.609/04/202121.0
Hou.DeerPrk2 C35/235/1001/AFH139FP239403/12/202132.901/17/202131.709/05/202128.707/11/202124.8
Seabrook Friendship Park C453 N09/05/202127.809/04/202125.401/17/202121.707/11/202119.3
Conroe Relocated C78/A3213 N09/05/202125.309/04/202122.705/03/202121.608/05/202121.4
Clinton C403/C304/AH113 3 N01/17/202126.805/03/202126.109/04/202124.909/05/202124.6
Houston North Wayside C405/C1033107/04/202128.508/05/202125.809/05/202125.209/04/202124.2
Houston Westhollow C410/C3003109/04/202132.009/05/202129.007/04/202125.505/03/202123.0
Park Place C4163 N01/16/202127.901/17/202127.203/23/202119.404/13/202115.4
UH West Liberty C6993 N01/17/202122.001/18/202112.301/16/202112.202/10/202111.3
Galveston 99th St. C1034/A320/X183209/04/202131.609/05/202126.507/11/202123.205/03/202120.0
Houston North Loop C1052207/05/202128.707/04/202127.509/05/202126.308/05/202124.8
Oyster Creek C1607 1 N09/04/202131.209/05/202125.201/16/202122.701/17/202121.3
San Antonio
San Antonio Northwest C23209/04/202127.707/24/202123.606/21/202121.909/05/202121.8
Calaveras Lake C59209/04/202125.904/09/202124.907/24/202121.203/27/202121.0
Heritage Middle School C6223 N04/09/202123.607/24/202122.107/12/202121.105/03/202120.4
Old Highway 90 C677/A3193 N09/04/202128.103/27/202127.507/24/202126.009/01/202125.3
San Antonio IH 35 C1069209/04/202125.904/09/202123.407/24/202121.409/05/202120.9
San Antonio Bulverde Parkway1 N09/04/202124.804/09/202123.407/24/202121.503/27/202121.0
New Braunfels Oak Run Parkway1 N09/04/202127.004/09/202124.307/24/202121.603/27/202121.4
Von Ormy Highway 16 C1090109/04/202128.305/03/202124.607/24/202123.604/09/202123.3
San Antonio Red Hill Lane C10911 N09/04/202126.404/09/202122.807/12/202122.307/24/202122.1
Corpus Christi-Victoria
Corpus Christi Huisache C98/A155304/09/202131.509/04/202128.605/03/202125.201/16/202122.2
Corpus Christi Huisache C98/A155404/09/202132.809/04/202132.105/03/202126.803/27/202124.6
National Seashore C314106/20/202138.805/04/202135.009/04/202134.906/21/202134.1
Dona Park C635/AF199/F2993 N09/04/202129.304/09/202123.805/03/202122.007/24/202121.9
Lower Rio Grande Valley
Mission C43/AP143204/09/202133.304/14/202130.009/04/202129.904/28/202128.0
Brownsville C80/AGP180201/26/202134.901/25/202133.909/04/202129.704/09/202128.3
Isla Blanca Park C323/C667109/04/202133.107/24/202131.009/03/202129.501/25/202127.6
World Trade Bridge C313104/14/202133.204/28/202132.507/12/202128.609/04/202127.8
Eagle Pass C319/C655104/28/202129.209/01/202125.107/24/202124.307/12/202124.3
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+ Not Defined
  • The AQI for PM-2.5 is based on a 24-hour average sampled from midnight to 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.