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AutoGC Data by Day by Parameter (all sites)

Use this form to retrieve hourly data collected at TCEQ Automated Gas Chromatograph (AutoGC) monitoring stations. 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.

This web page provides the most current hourly averaged data available. Our convention for time-tagging data is the beginning of each hour. For example, values shown for the noon hour are based on measurements taken from noon to 1:00 p.m. The noon average will not be calculated until after 1:00 p.m. The noon average will then be available on our external server from 1:15 p.m. to 1:30 p.m. This results in an apparent one-hour time lag in the data. We also present our data in Local Standard Time for each measuring site. For most of Texas this is Central Standard Time. During Daylight Savings, this introduces another apparent one-hour time lag in the data.

Select a date: Use the buttons below to select which date you want reported.
    Today (October 22, 2021)
    Yesterday (October 21, 2021)
    Specify a date
Select a Parameter: View hourly averages for any AutoGC parameter measured by the TCEQ. Select the parameter you are interested in from the list below. Data will be shown from all TCEQ monitoring sites that measure the parameter you select. Please note that not all parameters are measured at all sites.
      Measured in: ppb-Volume   ppb-Carbon
    * - Target Compound as of April 1998
    Air Monitoring Comparison Value Highlights:  Odor   Short-Term Vegetation   Short-Term Health   (if defined for a particular parameter)
    Report Format:  Tabular (webified)   Comma-delimited

Once you have made your selections above, click on the Generate Report button.

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.