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Daily Maximum Eight-Hour Ozone Averages for April 2018

The table below lists the peak daily maximum eight-hour ozone concentrations measured in April 2018 in each community where the TREX 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 2018POCMonitoring Site
12345678910111213141516171819
CT-ME-MA-NH-RI-VT
Sipayik TAQP-ME14945484446505045414146585550434342NV321Sipayik TAQP-ME
AreaMonitoring SitePOCApril 2018POCMonitoring Site
12345678910111213141516171819
CA-NV-AZ-HI-AS-GU
Cortina Rancheria-CA1 N00000000000000000NVNA1Cortina Rancheria-CA
Bishop Paiute Tribe Air-CA1 NNANV33353016293531282730233027212034261Bishop Paiute Tribe Air-CA
Fort McDowell Yuma Frank-AZ1 N515561576159474956586255495456516565341Fort McDowell Yuma Frank-AZ
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.
 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 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.