Peak Daily One-Hour Ozone Averages for May 2013

The table below lists the peak daily one-hour ozone concentrations measured in May 2013 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:
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember	20122013	Tabular (Web Formatted)Comma-Delimited	Include time
Highlight using AQI colors

Area	Monitoring Site	POC	May 2013																								POC	Monitoring Site
			1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
Southwest
	Rural Retreat	1	49	42	44	44	49	40	51	40	48	48	46	45	53	61	68	62	58	43	42	35	42	50	51	47	1	Rural Retreat
Area	Monitoring Site	POC	May 2013																								POC	Monitoring Site
			1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
Valley
	Albemarle High School	1	60	52	52	38	50	40	41	42	48	54	48	50	49	58	68	65	60	49	26	44	42	50	42	41	1	Albemarle High School
	Frederick Co. Public School Maint. Dept.	1	63	50	58	51	61	29	36	49	49	54	40	42	46	54	64	60	65	52	37	37	44	55	39	33	1	Frederick Co. Public School Maint. Dept.
	Luray Caverns Airport	1	63	51	53	45	55	43	46	44	49	54	47	50	50	57	67	62	63	48	35	47	44	54	47	38	1	Luray Caverns Airport
	Natural Bridge Station	1	55	50	46	40	49	36	38	38	49	54	44	47	49	57	64	60	50	47	28	42	38	41	41	41	1	Natural Bridge Station
	Harrisonburg VDOT	1	62	51	52	41	53	38	34	46	50	55	48	50	50	56	64	63	61	52	33	48	47	54	46	40	1	Harrisonburg VDOT
Area	Monitoring Site	POC	May 2013																								POC	Monitoring Site
			1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
Blue Ridge
	Herman L. Horn Elementary School	1	55	51	46	42	51	39	42	43	52	53	43	48	52	59	66	59	56	43	36	42	53	45	42	44	1	Herman L. Horn Elementary School
Area	Monitoring Site	POC	May 2013																								POC	Monitoring Site
			1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
Piedmont
	Shirley Plantation	1	45	44	45	39	42	35	41	40	46	51	47	52	45	53	66	63	65	51	32	30	39	36	27	38	1	Shirley Plantation
	Beach Road VDOT	1	51	44	50	40	45	37	50	42	47	56	48	53	47	56	67	66	67	52	34	36	36	42	38	41	1	Beach Road VDOT
	Hanover	1	50	42	47	40	45	36	44	40	48	59	51	50	48	58	71	72	65	47	39	41	43	48	39	38	1	Hanover
	MSIC (MathScience Innovation Center)	1	52	41	47	38	45	35	47	41	47	52	45	51	46	54	68	67	70	50	39	38	38	42	41	39	1	MSIC (MathScience Innovation Center)
Area	Monitoring Site	POC	May 2013																								POC	Monitoring Site
			1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
Tidewater
	NASA Langley Research Center	1	46	40	45	46	49	38	47	45	52	55	48	49	51	58	68	68	67	56	44	30	37	38	40	36	1	NASA Langley Research Center
	Tidewater Community College	1	48	38	43	45	50	37	49	41	48	55	51	51	51	56	71	68	63	53	40	29	33	34	39	38	1	Tidewater Community College
	VA Tech Agricultural Research Center	1	48	44	48	41	49	39	52	46	52	56	53	52	49	56	73	72	65	54	43	33	38	36	28	37	1	VA Tech Agricultural Research Center
Area	Monitoring Site	POC	May 2013																								POC	Monitoring Site
			1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
Northern
	Aurora Hills Visitor Center	1	55	41	46	45	52	38	32	48	49	62	44	46	48	54	70	61	83	51	43	46	49	56	51	35	1	Aurora Hills Visitor Center
	Fredericksburg Geomagnetic Observatory	1	52	41	49	45	50	37	40	43	48	61	46	51	50	57	68	66	61	45	33	38	42	47	50	39	1	Fredericksburg Geomagnetic Observatory
	Lee District Park - Fairfax County	1	57	42	48	45	51	38	30	44	46	58	43	46	49	55	67	63	80	50	40	39	43	50	46	36	1	Lee District Park - Fairfax County
	Sumerduck - C. Phelps Wildlife Mgmt Area	1	58	48	51	43	52	35	38	43	40	50	43	47	48	55	63	58	58	58	33	34	33	42	41	36	1	Sumerduck - C. Phelps Wildlife Mgmt Area
	Ashburn - Broad Run High School	1	61	47	52	48	56	33	35	48	50	53	43	45	50	56	65	58	69	51	42	41	47	52	46	36	1	Ashburn - Broad Run High School
	Shenandoah National Park - Big Meadows	1	NA	NA	NA	NA	NA	34	55	53	54	56	49	50	50	59	68	65	64	61	49	45	48	55	56	45	1	Shenandoah National Park - Big Meadows
	Long Park - Haymarket	1	62	48	54	50	59	32	46	47	47	54	44	45	47	56	66	58	67	55	36	40	39	46	44	34	1	Long Park - Haymarket
	Widewater Elem. School - Widewater	1	55	42	49	44	51	38	39	45	44	55	44	50	48	57	65	62	70	56	37	38	38	46	46	35	1	Widewater Elem. School - Widewater
NA - Data not available.

Interpreting the AQI

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.

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

• The AQI for ozone is based on either the peak eight-hour running average since midnight OR the peak one-hour measurement since midnight. When calculating air quality for the current day, the Virginia DEQ uses a surrogate 8-hour average based on the current hourly average.

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.