Latest Ozone Summary (PST)

California Environmental Protection Agency Air Resources Board

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Latest Ozone Summary for Selected Regions (Preliminary Data in PST)

Data on this page extracted on July 21, 2017 at 11:47:50

Note: The AQMIS Ozone pages reflect the 2015 National 8-Hour Ozone Standard of 0.070 ppm

Region	So Far Today (07/21/2017)		Yesterday (07/20/2017)		7 Days ending (07/20/2017)		This Year-to-Date through 07/20/2017
	So Far Today (07/21/2017)		Yesterday (07/20/2017)		7 Days ending (07/20/2017)		This Year-to-Date through 07/20/2017
	Max 1hr (ppm)	Latest hr (PST)	Max 1hr (ppm)	Max 8hr (ppm)	Max 1hr (ppm)	Max 8hr (ppm)	Max 1hr (ppm)	Max 8hr (ppm)
	Max 1hr (ppm)	Latest hr (PST)	Max 1hr (ppm)	Max 8hr (ppm)	Max 1hr (ppm)	Max 8hr (ppm)	Max 1hr (ppm)	Max 8hr (ppm)
Sacramento Metropolitan Area¹	0.063	9	0.087	0.079	0.098	0.083	0.121	0.091
San Diego Air Basin	0.042	9	0.076	0.063	0.084	0.071	0.108	0.095
San Francisco Bay Area Air Basin	0.028	9	0.051	0.040	0.075	0.063	0.094	0.071
San Joaquin Valley Air Basin	0.071	9	0.095	0.083	0.105	0.089	0.113	0.099
South Coast Air Basin	0.067	9	0.104	0.089	0.133	0.115	0.158	0.135
Ventura County (Mainland Only)	0.047	9	0.075	0.063	0.087	0.068	0.101	0.094
Antelope Valley and W. Mojave Desert	0.070	9	0.089	0.081	0.126	0.109	0.156	0.116
Coachella Valley	0.062	9	0.082	0.067	0.099	0.087	0.113	0.097
Eastern Kern County	0.067	9	0.079	0.069	0.097	0.085	0.097	0.085
Imperial County	0.040	9	0.049	0.040	0.091	0.062	0.119	0.092
Lake County²	N/A	N/A	N/A	N/A	N/A	N/A	0.049	0.048
Mountain Counties - Central	0.037	9	0.063	0.058	0.087	0.072	0.092	0.079
Mountain Counties - Southern	0.070	9	0.112	0.082	0.113	0.090	0.113	0.090
North Central Coast Air Basin	0.027	9	0.057	0.047	0.080	0.065	0.080	0.065
Sacramento Valley - Butte County	0.059	9	0.074	0.069	0.076	0.069	0.081	0.075
Sacramento Valley - Sutter Buttes³	0.055	9	0.083	0.070	0.083	0.070	0.087	0.079
Sacramento Valley (remaining areas)	0.071	9	0.077	0.066	0.077	0.072	0.113	0.084
San Luis Obispo County	0.047	9	0.061	0.059	0.076	0.069	0.091	0.080
Santa Barbara County	0.032	9	0.052	0.045	0.081	0.067	0.085	0.070
Western Nevada County	0.086	9	0.090	0.083	0.102	0.098	0.108	0.098


	N/A: Data not available
	To see monitoring site details, click on the numeric value for today, yesterday or 7 days.
	To see underlying daily data for area, click on the year-to-date numeric value.
	To see historical trend for area, click on area name.
	Cell color is red if national 8-hour standard level is exceeded; Nat'l stds truncate 4 digit 8-hr avg to 3 decimals.


¹	The Sacramento Metropolitan Area includes Sacramento Metropolitan Air Quality Management District, Yolo-Solano Air Pollution Control District, the southern third of Feather River Air Quality Management District, and all of El Dorado and Placer Counties except for that portion in the Lake Tahoe Air Basin.
²	The Lake County Air Quality Management District is a non-real time data stream that will be updated monthly.
³	Seasonal Ozone Sites

Standards:
State 1-hr: 0.090 ppm
State 8-hr: 0.070 ppm
National 1-hr: 0.12 ppm
2008 National 8-hr: 0.075 ppm
2015 National 8-hr: 0.070 ppm
Other Standards (pdf)

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Latest Ozone Summary for Selected Regions (Preliminary Data in PST)