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Peak Daily One-Hour Ozone Averages for April 2017

The table below lists the peak daily one-hour ozone concentrations measured in April 2017 in each community where the TREX measures ozone. Concentrations are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.) All ozone measurements are in parts per billion, and are truncated to an integer number.

The values that go into this table are calculated at 3:30 am each morning. Therefore, the current day will almost always have very low hourly averages that are not truly representative of local conditions for the day. Because of this, the report does not display the current day's data.

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 using AQI colors
AreaMonitoring SitePOCApril 2017POCMonitoring Site
1234567891011121314151617181920212223242526272829
CT-ME-MA-NH-RI-VT
Sipayik TAQP-ME148514850474447364358604435486051434147454446343865444136481Sipayik TAQP-ME
AreaMonitoring SitePOCApril 2017POCMonitoring Site
1234567891011121314151617181920212223242526272829
NJ-NY-PR-VI
Saint Regis Mohawk Tribe-NY1445443345643456545434344434541Saint Regis Mohawk Tribe-NY
AreaMonitoring SitePOCApril 2017POCMonitoring Site
1234567891011121314151617181920212223242526272829
CA-NV-AZ-HI-AS-GU
Cortina Rancheria-CA1 NNANANANANANANANANANANANANANANANANANANANANANANANANANANANANA1Cortina Rancheria-CA
Bishop Paiute Tribe Air-CA1 N24283740433825342941374031394137212441344143352933273733331Bishop Paiute Tribe Air-CA
Fort McDowell Yuma Frank-AZ1 N50635854556563616971706969657376666163726969636663676561471Fort McDowell Yuma Frank-AZ
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.