Daily Air Quality Index summaries from EPA monitors in Bannock, Idaho, 1986–2025.
89%
Good days in 2025
36
Median daily AQI, 2025
1
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 Bannock, Idaho on 365 days. 324 of those days (89%) were in the Good range, and the median daily AQI was 36. That median is about the same as the typical monitored county in Idaho (median 35 across 18 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 157 days. Across the years with fuller monitoring, the share of Good days rose: an average of 68% in 1989–1991 versus 85% in 2023–2025.
Years with fewer than 120 monitored days (1986, 1987, 1988) 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
Fine particles (PM2.5)
157
43%
Ozone
138
38%
Coarse particles (PM10)
70
19%
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
324
40
1
0
0
0
36
52
111
PM2.5
2024
366
286
78
2
0
0
0
39
59
104
PM2.5
2023
365
322
41
2
0
0
0
38
54
110
Ozone
2022
365
270
93
2
0
0
0
40
67
140
PM2.5
2021
365
245
112
7
1
0
0
44
76
155
PM2.5
2020
362
284
72
2
4
0
0
38
61
165
PM2.5
2019
365
330
35
0
0
0
0
24
50
64
PM2.5
2018
365
298
63
2
2
0
0
29
60
174
PM2.5
2017
365
225
134
3
3
0
0
38
69
168
PM2.5
2016
366
266
100
0
0
0
0
36
58
86
PM2.5
2015
365
295
66
3
1
0
0
34
56
158
PM2.5
2014
365
301
64
0
0
0
0
32
55
99
PM2.5
2013
365
263
100
2
0
0
0
38
65
130
PM2.5
2012
366
225
134
4
3
0
0
42
69
180
PM2.5
2011
365
320
44
1
0
0
0
24
54
101
PM10
2010
365
335
30
0
0
0
0
23
47
83
PM2.5
2009
362
316
43
3
0
0
0
26
53
141
PM2.5
2008
347
304
41
2
0
0
0
22
52
112
PM2.5
2007
311
284
27
0
0
0
0
19
47
99
PM2.5
2006
354
331
23
0
0
0
0
19
44
79
PM2.5
2005
353
299
51
3
0
0
0
19
59
122
PM2.5
2004
334
314
19
0
1
0
0
18
37
161
PM10
2003
267
257
10
0
0
0
0
19
44
80
PM10
2002
356
291
62
3
0
0
0
25
68
121
PM2.5
2001
363
246
104
13
0
0
0
39
77
140
PM2.5
2000
244
188
51
2
3
0
0
31
63
163
PM10
1999
242
185
51
3
3
0
0
38
57
195
PM10
1998
242
223
15
2
2
0
0
31
48
180
PM10
1997
338
319
19
0
0
0
0
31
46
98
PM10
1996
364
318
45
1
0
0
0
36
51
119
PM10
1995
365
337
28
0
0
0
0
33
45
72
NO2
1994
244
211
33
0
0
0
0
31
53
92
PM10
1993
173
151
21
1
0
0
0
31
52
139
PM10
1992
154
91
63
0
0
0
0
43
63
98
PM10
1991
158
115
42
1
0
0
0
38
60
114
PM10
1990
182
132
48
1
1
0
0
38
59
153
PM10
1989
182
109
70
3
0
0
0
44
68
114
PM10
1988
108
66
39
3
0
0
0
41
73
109
PM10
1987
62
50
12
0
0
0
0
36
59
83
PM10
1986
63
37
24
2
0
0
0
44
64
103
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 Idaho with a similar median AQI in 2025
