Historical Ozone Air Quality Trends

OZONE, 1980 - 2020

Number of Basin-Days Exceeding Health Standard Levels^a)

Year	Old Federal Standard 1-hour average > 0.12 ppm	1997 Federal Standard 8-hour average > 0.08 ppm	2008 Federal Standard 8-hour average > 0.075 ppm	2015 Federal Standard 8-hour average > 0.070 ppm	Health Advisory 1-hour average ≥ 0.15 ppm	Stage 1 Episode 1-hour average ≥ 0.20 ppm	Basin Maximum 1-hour average ppm	Basin Maximum 8-hour average ppm
2020	27	97	142	157	9	0	0.185	0.139
2019	10	71	101	126	0	0	0.137	0.117
2018	11	59	108	141	0	0	0.142	0.125
2017	28	82	121	145	3	0	0.158	0.136
2016	19	63	103	132	2	0	0.163	0.121
2015	11	47	81	113	0	0	0.144	0.127
2014	10	54	92	126	0	0	0.141	0.110
2013	6	56	88	116	1	0	0.151	0.122
2012	12	65	111	138	0	0	0.147	0.112
2011	17	71	106	122	1	0	0.160	0.136
2010	7	63	102	123	0	0	0.143	0.123
2009	17	81	113	129	3	0	0.176	0.128
2008	28	80	119	140	7	0	0.176	0.131
2007	19	78	108	126	5	0	0.171	0.137
2006	37	85	114	129	8	0	0.175	0.142
2005	32	83	116	136	8	0	0.182	0.145
2004	31	88	115	148	2	0	0.163	0.145
2003	66	109	133	151	26	0	0.194	0.153
2002	48	96	132	146	15	0	0.169	0.144
2001	37	92	128	154	13	0	0.190	0.144
2000	37	94	126	145	10	0	0.184	0.149
1999	39	93	120	144	6	0	0.174	0.142
1998	61	93	120	138	38	11	0.244	0.206
1997	66	118	155	174	22	1	0.205	0.148
1996	85	115	141	163	46	6	0.239	0.173
1995	98	120	150	170	57	11	0.256	0.203
1994	119	148	164	175	88	19	0.30	0.208
1993	124	161	183	205	92	23	0.28	0.195
1992	142	173	191	199	108	41	0.30	0.218
1991	130	160	176	188	101	47	0.32	0.203
1990	132	161	181	193	107	43	0.33	0.193
1989	157	181	210	221	120	54	0.34	0.252
1988	178	194	207	215	145	78	0.35	0.258
1987	161	179	190	198	130	66	0.33	0.210
1986	164	189	208	219	140	79	0.35	0.251
1985	158	180	200	207	136	83	0.39	0.288
1984	175	190	203	214	147	97	0.34	0.248
1983	152	168	181	191	139	87	0.39	0.258
1982	150	164	182	196	126	67	0.40	0.265
1981	184	196	212	225	166	102	0.37	0.282
1980	167	179	199	211	153	102	0.49	0.336

ppm = parts per million parts of air, by volume.
a) Basin-days represents the number of days a standard was exceeded anywhere in the South Coast Air Basin.

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South Coast Air Basin Ozone Trends (CSV, 1kb)

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Historical Ozone Air Quality Trends

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