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Daily Maximum Eight-Hour Ozone Averages for April 2019

The table below lists the peak daily maximum eight-hour ozone concentrations measured in April 2019 in each community where the DAQ measures ozone. Concentrations that are rated Moderate or higher are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.) All ozone measurements are in parts per billion.

Use the selection boxes below to customize this report. You may select a different month, a different year, a different report format, and whether or not to include time on the report. Click on the Generate Report button once you have made your selections.

Month:Year:Report Format: Include time:
Include time
Highlight with AQI colors
AreaMonitoring SitePOCApril 2019POCMonitoring Site
1234567891011121314151617181920
Clark County
Apex1485754504947514856484942486259NVNV4247351Apex
Mesquite14656484546444547554247434659625346NV43251Mesquite
Paul Meyer150565152465156535851504657655947515052431Paul Meyer
Walter Johnson149545051NV5058525750504556635846514851381Walter Johnson
Palo Verde14549NV47404553485547433852605440494549401Palo Verde
Joe Neal1NV50454642455249534745NANANANV44494651401Joe Neal
Green Valley1535951504851575358NV514557666449494452541Green Valley
Jerome Mack15257524947NVNANANANANV4556636046504651321Jerome Mack
Boulder City150575349485349505849534851636248494549531Boulder City
Jean154594952464949505650504654676249535050591Jean
Indian Springs150534552474547495448494554605345464052381Indian Springs
POC (Parameter Occurrence Code): a code used to correctly separate data from multiple instruments at one site.
NV - There are not enough valid eight-hour averages for this day (there must be eighteen valid eight-hour averages).
NA - Data not available.

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 - 0.054
51 - 100 Not Defined 0.055 - 0.070
101 - 150 0.125 - 0.164 0.071 - 0.085
151 - 200 0.165 - 0.204 0.086 - 0.105
201 - 300 0.205 - 0.404 0.106 - 0.200
301 - 400 0.405 - 0.504 0.201 - 0.2011
401 - 500 0.505 - 0.604 Not Defined
500+ Not Defined Not Defined

PLEASE NOTE: This data has not been verified by the Clark County Department of Air Quality 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 Clark County Department of Air Quality 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.