Daily Air Quality Index summaries from EPA monitors in Gila, Arizona, 1985–2025.
63%
Good days in 2025
47
Median daily AQI, 2025
15
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 Gila, Arizona on 365 days. 229 of those days (63%) were in the Good range, and the median daily AQI was 47. That median is about the same as 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 ozone on 287 days. Across the years with fuller monitoring, the share of Good days fell: an average of 87% in 1989–1991 versus 60% in 2023–2025.
Years with fewer than 120 monitored days (1985, 1986, 1987, 1988, 1992) 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
287
79%
Coarse particles (PM10)
73
20%
Fine particles (PM2.5)
5
1%
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
229
121
14
1
0
0
47
87
196
Ozone
2024
366
193
144
27
2
0
0
50
97
159
Ozone
2023
365
232
121
11
1
0
0
46
84
154
Ozone
2022
365
245
102
16
2
0
0
45
84
177
Ozone
2021
365
239
116
8
2
0
0
46
80
180
Ozone
2020
366
256
99
8
3
0
0
44
74
174
Ozone
2019
365
210
139
16
0
0
0
48
87
146
Ozone
2018
365
220
122
22
1
0
0
47
87
171
Ozone
2017
365
247
109
8
1
0
0
44
74
161
Ozone
2016
366
256
108
2
0
0
0
44
71
115
Ozone
2015
365
258
102
5
0
0
0
43
74
129
Ozone
2014
365
251
110
4
0
0
0
45
71
150
Ozone
2013
365
197
156
11
0
1
0
49
84
276
Ozone
2012
364
148
187
28
1
0
0
54
97
163
Ozone
2011
365
208
141
16
0
0
0
48
87
143
PM10
2010
362
237
122
3
0
0
0
44
77
136
Ozone
2009
307
169
132
6
0
0
0
48
84
136
Ozone
2008
266
129
108
29
0
0
0
51
101
147
Ozone
2007
336
134
179
23
0
0
0
56
93
126
Ozone
2006
353
173
145
34
1
0
0
51
100
159
Ozone
2005
272
109
129
32
2
0
0
58
108
182
Ozone
2004
265
125
121
19
0
0
0
51
93
133
Ozone
2003
256
67
142
44
3
0
0
68
112
169
Ozone
2002
226
76
131
14
5
0
0
61
100
164
Ozone
2001
121
84
37
0
0
0
0
37
65
95
PM2.5
2000
151
101
50
0
0
0
0
42
71
86
PM2.5
1999
279
128
128
23
0
0
0
52
100
147
Ozone
1998
189
132
55
2
0
0
0
36
71
122
Ozone
1997
190
170
19
1
0
0
0
38
51
102
PM2.5
1996
143
129
14
0
0
0
0
29
50
61
PM2.5
1995
141
126
15
0
0
0
0
28
51
99
PM2.5
1994
148
135
13
0
0
0
0
27
47
69
PM2.5
1993
134
120
14
0
0
0
0
28
51
88
PM2.5
1992
116
106
10
0
0
0
0
27
48
66
PM2.5
1991
142
131
11
0
0
0
0
27
49
89
PM2.5
1990
129
114
15
0
0
0
0
30
52
60
PM2.5
1989
130
103
27
0
0
0
0
34
54
93
PM2.5
1988
106
84
20
2
0
0
0
34
61
118
PM2.5
1987
61
42
17
2
0
0
0
38
81
118
PM10
1986
56
24
31
1
0
0
0
54
87
145
PM10
1985
51
21
29
1
0
0
0
54
82
102
PM10
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
