Air Quality Index

How clean is the air in your metropolitan area? The U. S. Environmental Protection Agency (EPA) has provided a scale called the Air Quality Index (AQI) for rating air quality. This scale is based on the National Ambient Air Quality Standards (NAAQS) and is described in the Code of Federal Regulations, Part 58, Appendix G. This report is based on the AQI standards.

Interpreting the AQI

Reporting for November 21, 2008 as of 3:22 pm PST
Emulate WWW

Metropolitan or
Other Area Air Quality Critical
Pollutant Air Quality Index Rating

Ozone Carbon Monoxide Sulfur Dioxide PM-10 PM-2.5

1-Hour 8-Hour 8-Hour 24-Hour † 24-Hour † 24-Hour †

AQI ppb AQI ppb AQI ppm AQI ppb AQI ug/m3 AQI ug/m3

Clark County

Apex    Good Ozone * 45 26 31 14 15.4 12 3.7

Boulder City    Good Ozone * 25 16 19 15 16.0

Greater Las Vegas ¹    Moderate PM-2.5 * 39 25 29 25 2.2 57 67.5 60 20.2

Jean    Good Ozone * 42 24 28 11 11.9 20 6.2

Mesquite    Good PM-10 * 36 13 15 15 16.3

† This is an average since midnight for the current day and does not represent an entire day's worth of data.

¹ Not all monitors are reporting for this metropolitan area.

* There is no AQI associated with hourly ozone averages less than 0.125 ppm (125 ppb).

Missing Data Report

Metropolitan Area Site Missing Parameter

PLEASE NOTE:   Data in this table is collected from DAQEM air monitoring sites, local agencies, and private monitoring networks. Site specific information is available for each metropolitan area by clicking on the metropolitan area name. This data has not been verified by DAQEM or the responsible entity and may change. While this is the most current data, it is not official until it has been certified by the appropriate technical staff. This table is updated hourly. Click here for information about all the monitoring sites.

Reporting for November 21, 2008 as of 3:22 pm PST Emulate WWW
Metropolitan or Other Area	Air Quality	Critical Pollutant	Air Quality Index Rating
Ozone	Carbon Monoxide	Sulfur Dioxide	PM-10	PM-2.5
1-Hour	8-Hour	8-Hour	24-Hour †	24-Hour †	24-Hour †
AQI	ppb	AQI	ppb	AQI	ppm	AQI	ppb	AQI	ug/m3	AQI	ug/m3
Clark County
	Apex		Good	Ozone	*	45	26	31				14	15.4	12	3.7
	Boulder City		Good	Ozone	*	25	16	19				15	16.0
	Greater Las Vegas ¹		Moderate	PM-2.5	*	39	25	29	25	2.2		57	67.5	60	20.2
	Jean		Good	Ozone	*	42	24	28				11	11.9	20	6.2
	Mesquite		Good	PM-10	*	36	13	15				15	16.3
† This is an average since midnight for the current day and does not represent an entire day's worth of data.
¹ Not all monitors are reporting for this metropolitan area.
* There is no AQI associated with hourly ozone averages less than 0.125 ppm (125 ppb).

Missing Data Report
Metropolitan Area	Site	Missing Parameter

The table above lists the current peak concentrations for each pollutant, the corresponding Air Quality Index (AQI) category, and the AQI ratings for each of the NAAQS pollutants that are measured real-time. The table is updated each hour and covers the period from midnight through the indicated ending time for today's data or from midnight to midnight on other days. Listings are provided for each area where monitoring sites are located. Critical pollutant concentrations for ozone and sulfur dioxide are shown in parts per billion (ppb), carbon monoxide measurements are shown in parts per million (ppm), and particulate matter (PM-10 and PM-2.5) concentrations are shown in micrograms per cubic meter (ug/m3).