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Ozone Hourly Averages

Ozone is a form of oxygen with three atoms instead of the usual two atoms. It is a photochemical oxidant and, at ground level, is the main component of smog. Unlike other gaseous pollutants, ozone is not emitted directly into the atmosphere. Instead, it is created in the atmosphere by the action of sunlight on volatile organic compounds and nitrogen oxides.

In Texas, higher levels of ozone usually occur on sunny days with light winds, primarily from March through October. An ozone exceedance day is counted if the measured eight-hour average ozone concentration exceeds the standards.

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Ozone Hourly Averages for Thursday, March 23, 2023.
measured in parts per billion
Mid 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:0010:0011:00Noon 1:00 2:00 3:00 4:00 5:00 6:00
San Antonio - all times are in CST
23 242121232222211919202224252730323233 NA 23 2 R MDL TCEQ
58 262524232323232020212325262931333334 NA 58 1 R MDL TCEQ
59 252425242422212021232425262930323433 NA 59 1 R MDL TCEQ
501  1 222121211919181818202021232425282931 NA 501  1 1 N MDL Oth Gov
502  1 222019191919191716171920212326272828 NA 502  1 1 N MDL Oth Gov
503  1 1918181717171715 QAS QAS1216181922232526 NA 503  1 1 N MDL TCEQ
504  1 191817191918171718192122242524252524 NA 504  1 1 N MDL TCEQ
505  2 201917181819151314171921222425262727 NA 505  2 1 N MDL Other Gov
506  1 242323232424232222232424262727272826 NA 506  1 1 N MDL TCEQ
622  3 222122212120191818192022232627293130 NA 622  3 1 N MDL TCEQ
678  3 141313141414111213141416171920202020 NA 678  3 1 N TCEQ
1610  3 181515151615141414141617181919212425 NA 1610  3 1 N MDL TCEQ
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- These sites are maintained and operated by Weston Solutions for AACoG.
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TCEQ does not certify the validity or quality of data it hosts from other monitoring entities.
Maximum values for the day are bold within the table. Minimum values are bold italic.
 R - Data from this instrument meets EPA quality assurance criteria for regulatory purposes.
 N - Data from this instrument does not meet EPA quality assurance criteria and cannot be used for regulatory purposes.

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.