Daily Air Quality Index summaries from EPA monitors in Inyo, California, 1980–2025.
37%
Good days in 2025
55
Median daily AQI, 2025
13
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)
In 2025, EPA reported a daily Air Quality Index (AQI) for Inyo, California on 365 days. 136 of those days (37%) were in the Good range, and the median daily AQI was 55. That median is higher than the typical monitored county in California (median 45.5 across 46 counties), and higher than the typical monitored U.S. county (40). The main pollutant was ozone on 234 days. Across the years with fuller monitoring, the share of Good days fell: an average of 89% in 1980–1991 versus 30% in 2023–2025.
Years with fewer than 120 monitored days (1986, 1987, 1988, 1989, 1990) are shown in the table but left out of comparisons and trend statements.
How the days broke down each year
Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.
Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous
Typical and high-end AQI over time
The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.
Median daily AQI
90th-percentile daily AQI
Main pollutant by day, 2025
On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.
Pollutant
Days as main pollutant
Share of monitored days
Ozone
234
64%
Fine particles (PM2.5)
117
32%
Coarse particles (PM10)
14
4%
Year-by-year data
Annual AQI summary by year
Year
Days with AQI
Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous
Median AQI
90th pct.
Max AQI
Main pollutant
2025
365
136
216
9
1
2
1
55
81
411
Ozone
2024
366
90
246
17
7
2
4
61
93
1322
Ozone
2023
365
106
236
13
3
1
6
61
90
786
Ozone
2022
365
117
217
18
4
4
5
58
97
1551
Ozone
2021
365
100
223
24
12
3
3
61
115
558
PM2.5
2020
366
158
153
23
16
8
8
57
130
705
Ozone
2019
365
226
127
6
2
1
3
47
84
653
Ozone
2018
365
192
136
26
7
2
2
49
101
638
Ozone
2017
365
195
145
16
3
0
6
49
87
2234
Ozone
2016
366
238
105
15
4
1
3
45
87
418
Ozone
2015
365
191
153
12
6
0
3
49
90
1482
Ozone
2014
365
222
128
6
5
1
3
48
84
957
Ozone
2013
365
219
125
10
7
2
2
47
87
417
Ozone
2012
366
198
139
15
4
2
8
49
93
4182
Ozone
2011
365
159
160
33
5
2
6
54
105
14703
Ozone
2010
365
236
98
13
1
6
11
44
93
4909
Ozone
2009
365
215
128
5
5
5
7
48
87
1503
Ozone
2008
366
197
134
22
9
0
4
49
100
733
Ozone
2007
365
168
148
38
8
1
2
51
112
637
Ozone
2006
365
176
123
47
8
1
10
51
115
9055
Ozone
2005
365
168
127
46
9
3
12
51
133
4262
Ozone
2004
366
167
139
35
2
3
20
57
119
5637
Ozone
2003
365
179
120
42
5
1
18
51
132
18304
Ozone
2002
365
159
126
39
10
5
26
60
158
8628
Ozone
2001
365
155
138
32
6
2
32
58
184
22897
Ozone
2000
366
184
123
32
4
2
21
50
126
11880
Ozone
1999
365
150
157
39
8
0
11
58
115
3054
Ozone
1998
365
190
123
40
3
3
6
50
112
1456
Ozone
1997
365
230
102
23
3
2
5
46
98
2307
Ozone
1996
366
224
102
27
6
0
7
44
102
2478
Ozone
1995
365
272
66
8
4
3
12
40
80
4197
Ozone
1994
364
182
123
43
7
4
5
51
115
1364
Ozone
1993
365
276
67
9
6
3
4
38
71
697
Ozone
1992
363
296
60
3
1
2
1
42
67
413
Ozone
1991
132
120
10
2
0
0
0
22
44
114
PM10
1990
76
66
6
1
0
0
3
23
56
791
PM10
1989
68
46
18
1
1
0
2
37
81
1897
PM10
1988
79
58
19
0
1
1
0
34
69
257
PM10
1987
69
53
11
4
0
0
1
33
84
576
PM10
1986
12
12
0
0
0
0
0
20
27
27
PM10
1981
198
171
25
2
0
0
0
38
54
108
Ozone
1980
175
155
18
2
0
0
0
37
51
101
Ozone
What this data can and can’t tell you
It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.
It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.
Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.
Counties in California with a similar median AQI in 2025
