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Daily Maximum Eight-Hour Ozone Averages for December 2017

The table below lists the peak daily maximum eight-hour ozone concentrations measured in December 2017 in each community where the Virginia DEQ 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 SitePOCDecember 2017
123456789101112131415
Southwest
Rural Retreat1383540423731322833313534343112
AreaMonitoring SitePOCDecember 2017
123456789101112131415
Valley
Albemarle High School1332433313332322926273235342625
Frederick Co. Public School Maint. Dept.1292325342530292322252934342424
Natural Bridge Station13426333430NV323025273234343121
Harrisonburg VDOT12729293635NV322418262835342415
AreaMonitoring SitePOCDecember 2017
123456789101112131415
Blue Ridge
Herman L. Horn Elementary School13730373825342927252832NV363019
AreaMonitoring SitePOCDecember 2017
123456789101112131415
Piedmont
Charles City County1332032312624302728252833332727
Beach Road VDOT1292227262725292220253033332822
Hanover1342332332927302827253035342630
MSIC (MathScience Innovation Center)1321729312325282725232931312226
AreaMonitoring SitePOCDecember 2017
123456789101112131415
Tidewater
NASA Langley Research Center1312931353425273535252632332829
Tidewater Community College1292427273122223534242333322826
VA Tech Agricultural Research Center1332433323421253132263133343325
AreaMonitoring SitePOCDecember 2017
123456789101112131415
Northern
Aurora Hills Visitor Center1251725262729292121212732312725
Fredericksburg Geomagnetic Observatory1322633343430322420223235352728
Lee District Park - Fairfax County1292328262830312222222834342729
Sumerduck - C. Phelps Wildlife Mgmt Area1322933363533322721263334362724
Ashburn - Broad Run High School1302328303233322324253035352716
Shenandoah National Park - Big Meadows1353740424336343432323635373123
Long Park - Haymarket1332330313133322726263036362922
Widewater Elem. School - Widewater1312429323334292423243035352630
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).

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 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 Virginia DEQ 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 Virginia DEQ 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.