Daily Air Quality Index summaries from EPA monitors in Bonner, Idaho, 1986–2025.
56%
Good days in 2025
47
Median daily AQI, 2025
4
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 Bonner, Idaho on 365 days. 205 of those days (56%) were in the Good range, and the median daily AQI was 47. That median is higher than the typical monitored county in Idaho (median 35 across 18 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 357 days. Across the years with fuller monitoring, the share of Good days fell: an average of 86% in 1989–1991 versus 69% in 2023–2025.
Years with fewer than 120 monitored days (1987, 1988, 1993, 1994, 1995, 1996…) 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)
357
98%
Coarse particles (PM10)
8
2%
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
205
156
4
0
0
0
47
66
138
PM2.5
2024
365
272
89
4
0
0
0
32
60
125
PM2.5
2023
363
273
86
2
1
1
0
34
60
261
PM2.5
2022
364
259
97
5
2
1
0
35
66
216
PM2.5
2021
364
260
94
4
4
2
0
37
63
203
PM2.5
2020
365
283
72
5
5
0
0
32
58
190
PM2.5
2019
365
291
73
1
0
0
0
27
60
115
PM2.5
2018
363
258
89
11
4
1
0
39
64
270
PM2.5
2017
362
248
102
7
0
5
0
37
68
276
PM2.5
2016
366
317
49
0
0
0
0
27
55
83
PM2.5
2015
365
293
60
9
3
0
0
28
63
162
PM2.5
2014
321
319
2
0
0
0
0
10
22
62
PM10
2013
273
271
2
0
0
0
0
12
21
79
PM10
2012
356
356
0
0
0
0
0
8
19
36
PM10
2011
340
340
0
0
0
0
0
9
17
37
PM10
2010
321
319
1
1
0
0
0
9
19
106
PM10
2009
356
352
4
0
0
0
0
12
28
89
PM10
2008
360
359
1
0
0
0
0
12
24
62
PM10
2007
305
305
0
0
0
0
0
12
24
48
PM10
2006
351
349
2
0
0
0
0
14
29
57
PM10
2005
339
327
12
0
0
0
0
14
30
62
PM10
2004
345
338
7
0
0
0
0
13
32
63
PM10
2003
339
326
13
0
0
0
0
14
37
88
PM10
2002
364
343
21
0
0
0
0
18
41
95
PM10
2001
312
270
42
0
0
0
0
25
52
91
PM10
2000
362
312
48
2
0
0
0
23
53
124
PM10
1999
359
307
51
1
0
0
0
22
53
101
PM10
1998
120
104
16
0
0
0
0
24
55
88
PM10
1997
120
115
5
0
0
0
0
18
35
60
PM10
1996
113
108
5
0
0
0
0
19
38
93
PM10
1995
116
109
7
0
0
0
0
21
42
63
PM10
1994
105
83
21
1
0
0
0
31
64
102
PM10
1993
96
73
23
0
0
0
0
30
57
87
PM10
1992
151
134
15
1
0
0
1
24
53
354
PM10
1991
130
112
18
0
0
0
0
22
57
95
PM10
1990
140
120
18
2
0
0
0
25
55
132
PM10
1989
152
131
20
0
0
0
1
25
54
322
PM10
1988
93
70
20
3
0
0
0
33
66
133
PM10
1987
70
52
18
0
0
0
0
37
64
86
PM10
1986
58
47
10
1
0
0
0
28
69
107
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
