California Air Resources Board California Map with Basin Highlighted
Ozone Data Summaries (1980-1998)
South Coast Air Basin
Year Number of Days Standard Exceeded Ozone Concentrations in ppm
1 hour 8 hour
State
1hr
Federal
1hr
Federal
8hr
Max
1hr
3 Year
4th High*
EPDC*
Max
8hr
3 Year Avg
4th High*
1998 107 60 92 0.24 0.22 0.224 0.206 0.154
1997 144 64 118 0.21 0.22 0.229 0.148 0.148
1996 141 85 115 0.24 0.23   0.173 0.161
1995 153 98 120 0.26 0.25 0.249 0.203 0.165
1994 165 118 148 0.30 0.28 0.279 0.208 0.171
1993 185 124 161 0.28 0.30 0.297 0.195 0.177
1992 190 142 173 0.30 0.30 0.286 0.218 0.180
1991 184 130 160 0.32 0.31 0.304 0.203 0.182
1990 185 131 161 0.33 0.33 0.310 0.193 0.186
1989 211 157 181 0.34 0.33 0.320 0.252 0.192
1988 216 178 194 0.35 0.34 0.319 0.258 0.205
1987 196 160 178 0.33 0.35 0.344 0.210 0.217
1986 217 167 191 0.35 0.35 0.360 0.251 0.222
1985 207 158 181 0.39 0.36 0.375 0.288 0.226
1984 209 175 190 0.34 0.36 0.354 0.248 0.225
1983 192 153 169 0.39 0.36 0.365 0.258 0.229
1982 198 151 166 0.40 0.39   0.265 0.233
1981 233 187 199 0.39 0.42 0.401 0.282 0.251
1980 210 167 179 0.49 0.43 0.451 0.336 0.273
* The 3 year 4th high, 3 year average 4th high, and Expected Peak Day Concentration (EPDC) are calculated based on data for 3 successive years, listed by the last year of the three year period.  The EPDC represents the ozone concentration expected to occur once per year.
   

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This page last revised on March 26, 1999

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