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One-Hour Ozone High Value Days for 2019
as of October 18

In July 1997, the U. S. Environmental Protection Agency (EPA) announced a new National Ambient Air Quality Standard for ground-level ozone. The EPA is phasing out and replacing the previous one-hour standard with a new eight-hour standard to protect public health against longer exposure to the air pollutant.

A community will meet the new standard when the three-year average of the fourth-highest daily maximum eight-hour concentration measured at each monitoring site is less than 85 parts per billion.

Use the selection boxes below to customize this report. You may select a different year, a different sorting order, or a different report format. Click on the Generate Report button once you have made your selections. All times shown are in 24-hour format and are Local Standard Time. These times correspond to the beginning of the hourly average.

YearSort ByReport Format
Highlight with AQI colors
The table below lists the one-hour ozone concentrations measured in 2019 in each community where TREX measures ozone that are equal to or higher than 125 parts per billion. All ozone measurements are in parts per billion. Concentrations are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.)

2019 -- Sorted by Maximum Value
LocationRegionCAMSAQSDateTimeValuePOCHours
Exceeded
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 1 201906:001581 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 15 201908:001581 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 30 201907:001571 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 2 201906:001571 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 3 201906:001571 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 14 201907:001571 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 16 201908:001571 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 5 201906:001551 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 6 201909:001551 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 7 201907:001551 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 11 201906:001551 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 18 201910:001551 N14
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 21 201905:001541 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 29 201901:001541 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 10 201909:001541 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 2 201917:001531 N23
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 3 201917:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 4 201921:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 6 201917:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 7 201917:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 8 201919:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 9 201918:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 14 201917:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 28 201909:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 30 201914:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 31 201918:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 14 201920:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 25 201916:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 4 201917:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 8 201906:001531 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 5 201922:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 11 201916:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 12 201916:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 13 201918:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 16 201915:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 17 201919:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 18 201919:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 19 201922:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 21 201921:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 22 201917:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 23 201912:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 25 201918:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 26 201917:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 27 201921:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 29 201922:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 1 201920:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 2 201901:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 3 201918:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 4 201921:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 5 201914:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 6 201919:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 7 201919:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 8 201917:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 10 201916:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 11 201911:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 12 201912:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 13 201913:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 15 201918:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 16 201914:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 17 201916:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 18 201914:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 19 201916:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 20 201914:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 22 201910:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 26 201918:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 28 201923:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 17 201915:001521 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 10 201915:001511 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 15 201918:001511 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 20 201919:001511 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 24 201920:001511 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 9 201917:001511 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 24 201923:001511 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 27 201916:001511 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000September 23 201913:001501 N23
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 12 201905:001501 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 9 201908:001491 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000February 6 201919:001481 N2
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000October 13 201909:001441 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 26 201915:001431 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 24 201905:001431 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 21 201915:001411 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 12 201918:001411 N21
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 22 201914:001411 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 26 201914:001411 N18
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 27 201900:001411 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 19 201916:001401 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 30 201915:001401 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 11 201908:001401 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 19 201910:001401 N18
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 20 201919:001401 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 11 201908:001391 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 13 201917:001391 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 24 201922:001391 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 4 201921:001391 N17
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 5 201906:001391 N21
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 7 201913:001391 N21
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 8 201911:001391 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 29 201910:001391 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 30 201913:001391 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000August 1 201912:001391 N21
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 12 201915:001381 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 16 201914:001381 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 18 201920:001381 N15
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 20 201919:001381 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 27 201913:001381 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 29 201916:001381 N21
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 1 201915:001381 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 9 201918:001381 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 10 201919:001381 N18
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 13 201920:001381 N21
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 14 201911:001381 N17
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 15 201914:001381 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 18 201915:001381 N18
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 21 201903:001381 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 23 201904:001381 N24
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 10 201920:001371 N17
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 17 201913:001371 N16
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 28 201901:001371 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 2 201914:001371 N21
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 16 201905:001371 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 28 201912:001371 N22
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 14 201904:001361 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 23 201901:001361 N17
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 25 201914:001361 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 3 201903:001361 N18
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 25 201923:001361 N14
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 15 201908:001351 N19
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 22 201900:001351 N16
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 6 201921:001351 N15
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 31 201905:001351 N20
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 8 201916:001341 N6
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 4 201914:001331 N6
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000July 17 201917:001321 N14
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 5 201906:001291 N3
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 7 201911:001291 N4
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 6 201917:001281 N3
Las Vegas Paiute Air Monitoring Site-NV9800032_003_8000June 9 201915:001271 N6
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.

PLEASE NOTE: This data has not been verified by the TREX 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 TREX ambient monitoring sites and may include data collected by other outside agencies.

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 1hr Ozone
in ppm
8hr Ozone
in ppm
0 - 50 Not Defined 0 - 0.059
51 - 100 Not Defined 0.06 - 0.075
101 - 150 0.125 - 0.164 0.076 - 0.095
151 - 200 0.165 - 0.204 0.096 - 0.115
201 - 300 0.205 - 0.404 0.116 - 0.374
301 - 400 0.405 - 0.504 Not Defined
401 - 500 0.505 - 0.604 Not Defined
500+ Not Defined Not Defined

PLEASE NOTE: This data has not been verified by the TREX 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 TREX 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.