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Four Highest 24-Hour PM-2.5 Concentrations in 2021
as of January 24, 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 C320201/08/202110.001/22/20218.101/09/20217.501/24/20216.7
Lubbock 12th Street C1028101/22/20218.001/24/20217.101/23/20217.001/16/20213.7
Dallas-Fort Worth
Ft. Worth Northwest C13/AH302 301/09/202114.201/16/202113.901/18/202112.801/10/202112.8
Midlothian OFW C52/A1373 N01/12/202116.701/16/202111.101/04/20219.401/05/20218.7
Denton Airport South C56/A163/X157101/10/202113.101/13/202111.201/23/202110.901/09/20219.3
Kaufman C71/A304/X0713 N01/18/20218.501/19/20216.301/17/20216.301/22/20215.9
Haws Athletic Center C310201/09/202115.801/10/202112.901/18/202112.701/04/202112.6
Dallas Hinton St. C401/C60/AH161 401/11/202114.801/12/202114.401/04/202113.301/18/202112.3
Corsicana Airport C10513 N01/11/20217.901/16/20217.801/18/20217.401/17/20216.9
Ft Worth California Parkway North C1053201/09/202114.401/16/202114.101/04/202112.501/10/202112.3
Ft Worth California Parkway North C1053301/09/202114.701/16/202114.601/10/202112.301/04/202112.2
Karnack C85/AFHP3033 N01/19/20219.101/18/20218.301/12/20217.601/20/20217.3
Texarkana New Boston C1031201/12/202113.301/11/202112.801/19/202112.401/09/202111.9
El Paso-Juarez
El Paso UTEP C12/A125/X151/G1253 N01/01/202119.801/08/202116.201/07/202113.601/18/202112.5
Ascarate Park SE C37/A332/A172/X1593 N01/07/202115.901/17/202113.501/18/202112.301/08/202112.0
Chamizal C41/AH126 601/01/202117.001/08/202116.001/05/202115.801/23/202114.8
Socorro Hueco C49/F3123 N01/07/202114.401/15/202113.701/14/202113.601/08/202112.7
BRAVO Big Bend C67/C316/C656/C691101/09/20218.901/24/20216.401/19/20216.201/21/20215.2
Odessa Gonzales C1014 101/11/202114.801/12/202112.101/09/202110.701/24/202110.4
Waco Mazanec C10373 N01/16/202122.801/17/20219.601/18/20218.201/10/20217.3
Temple Georgia C1045101/16/202132.001/13/20218.601/17/20218.301/18/20217.8
Bryan Finfeather Road101/16/202127.601/11/202114.801/12/202112.001/17/202111.8
Beaumont-Port Arthur
Hamshire C64/C654201/17/202120.001/20/202113.101/12/202113.001/18/202111.3
Port Arthur Memorial School C303/C689401/17/202115.501/12/202114.501/03/202110.201/18/202110.0
SETRPC Mauriceville 42 C642/C311/C665101/17/202123.401/18/202113.701/20/202112.601/12/20219.2
Austin North Hills Drive C3/A322101/17/202114.501/16/202111.001/21/202110.201/12/20219.3
Austin Webberville Road AF171301/17/202120.401/16/202116.101/21/202112.901/09/202111.9
Austin North Interstate 35 C1068201/17/202124.601/16/202115.801/18/202114.201/21/202112.8
Jarrell FM 487 C10941 N01/16/202123.901/10/20217.601/22/20217.001/21/20217.0
Houston East C1/G316101/17/202147.401/16/202123.601/18/202121.901/20/202116.4
Houston Aldine C8/AF108/X150 401/17/202134.101/16/202127.401/18/202120.201/03/202120.2
Hou.DeerPrk2 C35/235/1001/AFH139FP239401/17/202133.301/16/202124.301/18/202117.501/12/202117.1
Seabrook Friendship Park C453 N01/17/202121.701/16/202117.001/18/202111.901/20/202110.5
Conroe Relocated C78/A3213 N01/17/202114.301/16/202113.201/20/202111.901/18/202111.3
Clinton C403/C304/AH113 3 N01/17/202128.901/16/202122.701/18/202120.001/20/202115.6
Houston Westhollow C410/C3003101/20/202117.201/22/20217.401/23/20216.301/21/20216.0
Park Place C4163 N01/16/202127.901/17/202127.201/18/202114.301/20/202113.9
UH West Liberty C6993 N01/17/202122.001/18/202112.301/16/202112.201/12/20218.5
Galveston 99th St. C1034/A320/X183201/17/202115.201/12/202112.801/16/202112.401/09/202110.1
Oyster Creek C1607 1 N01/16/202122.701/17/202121.301/12/202117.001/11/202114.1
San Antonio
San Antonio Northwest C23201/17/202114.501/21/202112.501/03/202110.701/13/20219.8
Calaveras Lake C59201/17/202114.901/21/202110.301/20/202110.001/23/20219.7
Heritage Middle School C6223 N01/17/202114.301/16/20219.201/18/20218.801/21/20218.3
Old Highway 90 C677/A3193 N01/17/202120.001/04/202118.901/03/202118.001/16/202117.3
San Antonio IH 35 C1069201/17/202113.801/03/202112.601/13/202111.901/21/202111.5
San Antonio Bulverde Parkway1 N01/17/202113.701/18/20219.001/21/20218.701/22/20217.7
New Braunfels Oak Run Parkway1 N01/04/202117.101/17/202111.301/05/202110.001/16/20219.6
Von Ormy Highway 16 C1090101/17/202114.301/18/202111.701/23/202111.201/13/20218.9
San Antonio Red Hill Lane C10911 N01/17/202114.801/22/20218.001/21/20218.001/19/20218.0
Corpus Christi-Victoria
Corpus Christi Huisache C98/A155301/16/202122.201/17/202114.401/24/202112.601/23/202112.3
Corpus Christi Huisache C98/A155401/16/202124.101/17/202116.301/23/202114.701/24/202113.8
National Seashore C314101/19/202118.001/16/202115.301/20/202113.201/17/202111.7
Dona Park C635/AF199/F2993 N01/16/202114.901/24/202112.101/17/202111.701/20/20219.2
Lower Rio Grande Valley
Mission C43/AP143201/16/202115.701/23/202113.801/24/202113.601/03/202111.6
Brownsville C80/AGP180201/24/202114.101/23/202113.201/01/202112.901/16/202112.5
Isla Blanca Park C323/C667101/23/202117.901/24/202115.301/19/202115.201/21/202110.5
World Trade Bridge C313101/24/202116.001/13/202110.901/19/20219.401/23/20218.9
Eagle Pass C319/C655101/18/202114.201/17/202114.001/22/202110.701/23/202110.5
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.