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Peak Daily One-Hour Ozone Averages for December 2017

The table below lists the peak daily one-hour ozone concentrations measured in December 2017 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 2017
1234567891011121314
Southwest
Rural Retreat14343444441323427393239353634
AreaMonitoring SitePOCDecember 2017
1234567891011121314
Valley
Albemarle High School13831403836363533282935373829
Frederick Co. Public School Maint. Dept.13332333829333226252932343528
Natural Bridge Station14032424038343631273037373733
Harrisonburg VDOT13333374038353328202932373730
AreaMonitoring SitePOCDecember 2017
1234567891011121314
Blue Ridge
Herman L. Horn Elementary School14034444134373530293135343833
AreaMonitoring SitePOCDecember 2017
1234567891011121314
Piedmont
Charles City County13624374029273425312833363429
Beach Road VDOT13227353532273224252835353531
Hanover13728384132303431302935363733
MSIC (MathScience Innovation Center)13624363926283231282733353326
AreaMonitoring SitePOCDecember 2017
1234567891011121314
Tidewater
NASA Langley Research Center13431364036293135362828333531
Tidewater Community College13230333333252939362728363531
VA Tech Agricultural Research Center13531403936252929342936353736
AreaMonitoring SitePOCDecember 2017
1234567891011121314
Northern
Aurora Hills Visitor Center12927323033323226242532323328
Fredericksburg Geomagnetic Observatory13629383739333528252536353731
Lee District Park - Fairfax County13229333433333426262632343629
Sumerduck - C. Phelps Wildlife Mgmt Area13533373939363529252937353832
Ashburn - Broad Run High School13429323637363429263034363631
Shenandoah National Park - Big Meadows14439464145383537363338373837
Long Park - Haymarket13531363636363432293034363731
Widewater Elem. School - Widewater13529373737383528272634353829

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.