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Peak Daily One-Hour Ozone Averages for October 2018

The table below lists the peak daily one-hour ozone concentrations measured in October 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 SitePOCOctober 2018POCMonitoring Site
Rural Retreat14145414438324334353131413425452436424837351Rural Retreat
AreaMonitoring SitePOCOctober 2018POCMonitoring Site
Albemarle High School14244423927283836332732413629312239384637361Albemarle High School
Frederick Co. Public School Maint. Dept.14335403529324438343322333328222834343833311Frederick Co. Public School Maint. Dept.
Natural Bridge Station13838393634353733272132393626292237364237381Natural Bridge Station
Harrisonburg VDOT14033373528383937313025373526302637364237351Harrisonburg VDOT
AreaMonitoring SitePOCOctober 2018POCMonitoring Site
Blue Ridge
Herman L. Horn Elementary School13943474340334538332232403731332338374537371Herman L. Horn Elementary School
AreaMonitoring SitePOCOctober 2018POCMonitoring Site
Charles City County15245554425354246413017NANA25422836383927351Charles City County
Beach Road VDOT14143424222463441372729403327372536363828341Beach Road VDOT
MSIC (MathScience Innovation Center)14744494422405143393229393433382836364028361MSIC (MathScience Innovation Center)
AreaMonitoring SitePOCOctober 2018POCMonitoring Site
NASA Langley Research Center16244454837364036373929403844393636384334351NASA Langley Research Center
Tidewater Community College16242465149364234343228393939363031394132351Tidewater Community College
VA Tech Agricultural Research Center14743385152424134343127354137383034384334341VA Tech Agricultural Research Center
AreaMonitoring SitePOCOctober 2018POCMonitoring Site
Aurora Hills Visitor Center14852474419283739353322353526243037344135331Aurora Hills Visitor Center
Fredericksburg Geomagnetic Observatory14252423721273633293630393728372738374234361Fredericksburg Geomagnetic Observatory
Lee District Park - Fairfax County14448484820253534313126363625233037364136341Lee District Park - Fairfax County
Sumerduck - C. Phelps Wildlife Mgmt Area13841353728193235312827353427312637353933361Sumerduck - C. Phelps Wildlife Mgmt Area
Ashburn - Broad Run High School14945454229304440393924363631242938364138341Ashburn - Broad Run High School
Shenandoah National Park - Big Meadows14042393833384140353338413937373039404643381Shenandoah National Park - Big Meadows
Long Park - Haymarket14244403828253938383426363532233037354136351Long Park - Haymarket
Widewater Elem. School - Widewater14544383921213332303328363625322637353835341Widewater Elem. School - Widewater
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.