Daily Air Quality Index summaries from EPA monitors in Pinal, Arizona, 1999–2025.
17%
Good days in 2025
67
Median daily AQI, 2025
34
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 Pinal, Arizona on 365 days. 62 of those days (17%) were in the Good range, and the median daily AQI was 67. That median is higher than the typical monitored county in Arizona (median 47 across 13 counties), and higher than the typical monitored U.S. county (40). The main pollutant was coarse particles (PM10) on 180 days. Across the years with fuller monitoring, the share of Good days fell: an average of 54% in 2000–2002 versus 23% in 2023–2025.
Years with fewer than 120 monitored days (1999) 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
Coarse particles (PM10)
180
49%
Ozone
138
38%
Fine particles (PM2.5)
47
13%
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
62
269
26
1
0
7
67
100
1215
PM10
2024
366
77
219
65
3
1
1
77
111
337
PM10
2023
365
109
211
38
5
1
1
64
105
709
PM10
2022
365
91
238
28
3
2
3
61
100
689
PM10
2021
365
72
240
49
4
0
0
70
108
198
PM10
2020
366
86
196
74
8
0
2
73
121
1194
PM10
2019
365
104
228
21
2
3
7
63
100
929
PM10
2018
365
71
243
34
6
3
8
67
108
1051
PM10
2017
365
55
242
59
7
1
1
75
115
358
PM10
2016
366
57
256
46
5
1
1
69
108
1348
PM10
2015
365
86
233
33
3
0
10
63
108
924
PM10
2014
365
51
227
55
17
3
12
72
142
924
PM10
2013
365
91
195
56
15
5
3
69
131
947
PM10
2012
366
46
237
69
7
3
4
75
124
605
PM10
2011
365
65
185
76
17
9
13
83
155
2403
PM10
2010
365
88
236
39
0
0
2
69
101
1786
PM10
2009
365
41
259
49
9
1
6
77
113
1435
PM10
2008
366
57
120
105
60
18
6
105
186
506
PM10
2007
365
39
118
116
49
19
24
108
221
2332
PM10
2006
365
20
93
101
92
22
37
132
305
1027
PM10
2005
365
179
147
37
2
0
0
51
101
177
Ozone
2004
366
210
140
16
0
0
0
48
90
122
Ozone
2003
365
163
150
47
5
0
0
58
108
172
Ozone
2002
365
176
150
38
1
0
0
51
101
199
Ozone
2001
223
102
98
23
0
0
0
52
101
147
Ozone
2000
120
81
38
1
0
0
0
43
57
123
PM2.5
1999
119
77
42
0
0
0
0
42
60
70
PM2.5
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 Arizona with a similar median AQI in 2025
