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Peak Daily One-Hour Ozone Averages for December 2018

The table below lists the peak daily one-hour ozone concentrations measured in December 2018 in each community where the Virginia DEQ 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 SitePOCDecember 2018
12345678910
Southwest
Rural Retreat141403724283532323445
AreaMonitoring SitePOCDecember 2018
12345678910
Valley
Albemarle High School115183630263134332733
Frederick Co. Public School Maint. Dept.118142829283130332332
Natural Bridge Station124203821293437312938
Harrisonburg VDOT17273426283034332321
AreaMonitoring SitePOCDecember 2018
12345678910
Blue Ridge
Herman L. Horn Elementary School118243723273132293138
AreaMonitoring SitePOCDecember 2018
12345678910
Piedmont
Charles City County1141730272828272926NA
Beach Road VDOT113173629283032332428
Hanover113173528272930312728
MSIC (MathScience Innovation Center)11293128262829302627
AreaMonitoring SitePOCDecember 2018
12345678910
Tidewater
NASA Langley Research Center129333428282728313128
Tidewater Community College128363126262629303026
VA Tech Agricultural Research Center132363523252932303126
AreaMonitoring SitePOCDecember 2018
12345678910
Northern
Aurora Hills Visitor Center13123128262727302126
Fredericksburg Geomagnetic Observatory18143932263235302428
Lee District Park - Fairfax County17123330262931342130
Sumerduck - C. Phelps Wildlife Mgmt Area19163731283134322232
Ashburn - Broad Run High School110143229283231332031
Shenandoah National Park - Big Meadows137373734313540394545
Long Park - Haymarket115123230303033352330
Widewater Elem. School - Widewater18113731292933342030
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 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.