California Air Resources Board
January - May
Year-to-Date Ozone Summary
for Selected California Monitoring Sites
   

Sacramento Valley Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Sacramento Folsom-
50 Natoma Street*
1995 0 0 0 0.089 0.073
1996 2 0 2 0.106 0.093
1997 3 0 2 0.105 0.090
1998** 0 0 0 0.07  0.065

Sacramento Sacramento-
Del Paso Manor
1995 2 0 1 0.104 0.085
1996 1 0 0 0.102 0.080
1997 2 0 0 0.097 0.083
1998** 0 0 0 0.08  0.072
* The 50 Natoma Street site replaced the Folsom-City Corporation Yard site in 1997.
** All 1998 data are preliminary and subject to further review.  
 
San Diego Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
San Diego Alpine-
Victoria Drive
1995 9 0 4 0.116 0.092
1996 10 1 6 0.133 0.117
1997 12 0 6 0.109 0.093
1998** 0 0 0 0.092 0.084

San Diego Escondido-
Valley Parkway
1995 0 0 0 0.087 0.075
1996 3 0 3 0.112 0.096
1997 0 0 0 0.092 0.083
1998** 0 0 0 0.094 0.082

San Diego Otay Mesa-
Paseo International
1995 2 0 0 0.113 0.078
1996 3 0 1 0.111 0.089
1997 3 0 0 0.100 0.079
1998** 0 0 0 0.072 0.060
** All 1998 data are preliminary and subject to further review.  
 
San Francisco Bay Area Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Alameda Livermore-
Old 1st Street
1995 0 0 0 0.082 0.063
1996 2 0 0 0.096 0.083
1997 0 0 0 0.074 0.058
1998** 0 0 0 0.087 0.062

Contra Costa Concord-
2975 Treat Blvd
1995 0 0 0 0.069 0.061
1996 1 0 1 0.109 0.089
1997 0 0 0 0.073 0.060
1998** 0 0 0 0.089 0.069

Santa Clara San Jose-
935 Piedmont Road
1995 0 0 0 0.072 0.061
1996 1 0 0 0.106 0.078
1997 0 0 0 0.080 0.063
1998** 0 0 0 0.051 0.047
** All 1998 data are preliminary and subject to further review.  
 
San Joaquin Valley Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Fresno Fresno-
1st Street
1995 5 1 3 0.126 0.100
1996 1 0 1 0.118 0.093
1997 5 0 3 0.119 0.098
1998** 1 0 1 0.10  0.087

Fresno Parlier 1995 0 0 0 0.084 0.072
1996 5 2 3 0.136 0.103
1997 9 0 5 0.116 0.090
1998** 0 0 0 0.094 0.083

Kern Arvin-
Bear Mountain Blvd
1995 5 0 2 0.104 0.091
1996 8 1 7 0.139 0.123
1997 4 0 4 0.117 0.100
1998** 0 0 0 0.09  0.080

Kern Edison 1995 8 0 8 0.112 0.098
1996 4 1 3 0.135 0.118
1997 4 0 2 0.108 0.086
1998** 0 0 0 0.09  0.077
** All 1998 data are preliminary and subject to further review.  
 
South Coast Air Basin
County Site Year Exceedance Days Maximum
State Federal Concentrations (ppm)
1-hr 1-hr 8-hr 1-hr 8-hr
Los Angeles Glendora-
Laurel
1995 10 5 5 0.177 0.131
1996 16 7 10 0.197 0.146
1997 19 4 8 0.164 0.120
1998** 2 0 0 0.110 0.078

Riverside Riverside-
Rubidoux
1995 9 3 7 0.136 0.110
1996 17 4 16 0.203 0.162
1997 27 3 19 0.152 0.129
1998** 1 0 1 0.100 0.086

San Bernardino Lake Gregory 1995 11 1 8 0.128 0.101
1996 22 10 18 0.234 0.151
1997 25 9 18 0.147 0.123
1998** 10 0 9 0.120 0.100

San Bernardino San Bernardino-
4th Street
1995 9 3 5 0.138 0.117
1996 21 7 16 0.239 0.173
1997 30 10 22 0.157 0.126
1998** 3 0 1 0.100 0.085
** All 1998 data are preliminary and subject to further review.  
 
 
Please send questions or comments to:
aqdweb@arb.ca.gov
 
This page last revised on June 3, 1998
 
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