Daily Air Quality Index summaries from EPA monitors in Brooke, West Virginia, 1985–2025.
73%
Good days in 2025
36
Median daily AQI, 2025
0
Days above 100 in 2025
308
Days with an AQI in 2025 (of 365)
In 2025, EPA reported a daily Air Quality Index (AQI) for Brooke, West Virginia on 308 days. 225 of those days (73%) were in the Good range, and the median daily AQI was 36. That median is lower than the typical monitored county in West Virginia (median 39 across 12 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 308 days. Across the years with fuller monitoring, the share of Good days fell: an average of 85% in 1991–1993 versus 79% in 2023–2025.
Years with fewer than 120 monitored days (1985, 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
Fine particles (PM2.5)
308
100%
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
308
225
83
0
0
0
0
36
57
80
PM2.5
2024
366
277
89
0
0
0
0
36
56
72
PM2.5
2023
362
316
43
2
1
0
0
19
52
183
PM10
2022
363
321
42
0
0
0
0
18
52
76
PM10
2021
362
295
67
0
0
0
0
21
56
83
PM10
2020
366
318
48
0
0
0
0
18
52
78
PM10
2019
360
287
72
1
0
0
0
19
56
112
PM10
2018
362
308
54
0
0
0
0
19
55
75
PM10
2017
363
297
66
0
0
0
0
18
57
74
PM10
2016
366
304
62
0
0
0
0
19
55
80
PM10
2015
365
295
70
0
0
0
0
17
61
92
PM10
2014
365
293
72
0
0
0
0
17
59
93
PM10
2013
365
291
74
0
0
0
0
16
58
97
PM10
2012
358
276
82
0
0
0
0
20
60
85
PM10
2011
283
200
82
1
0
0
0
21
67
111
PM10
2010
365
261
102
2
0
0
0
21
67
107
PM10
2009
365
276
87
2
0
0
0
19
62
133
PM10
2008
366
262
100
4
0
0
0
22
65
112
PM10
2007
365
248
111
6
0
0
0
27
75
138
PM10
2006
365
243
118
4
0
0
0
30
69
134
PM10
2005
365
246
111
8
0
0
0
28
78
147
PM10
2004
366
236
119
11
0
0
0
35
70
147
PM10
2003
364
239
120
4
1
0
0
32
74
156
PM10
2002
365
234
125
6
0
0
0
31
70
150
PM10
2001
365
240
117
8
0
0
0
34
74
142
PM10
2000
366
253
106
7
0
0
0
29
72
145
PM10
1999
365
236
120
8
1
0
0
30
77
152
PM10
1998
365
326
39
0
0
0
0
22
51
73
PM10
1997
365
344
21
0
0
0
0
20
43
81
PM10
1996
366
333
33
0
0
0
0
24
47
71
PM10
1995
365
303
61
1
0
0
0
30
54
116
PM10
1994
365
290
70
2
0
3
0
27
62
281
PM10
1993
352
299
52
1
0
0
0
27
55
131
PM10
1992
307
273
34
0
0
0
0
29
52
74
PM10
1991
172
140
32
0
0
0
0
32
54
91
PM10
1990
119
94
25
0
0
0
0
33
57
93
PM10
1989
49
37
12
0
0
0
0
35
54
77
PM10
1988
52
45
7
0
0
0
0
31
53
83
PM10
1987
59
50
9
0
0
0
0
32
57
80
PM10
1986
59
46
13
0
0
0
0
35
71
93
PM10
1985
52
39
13
0
0
0
0
40
62
76
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 West Virginia with a similar median AQI in 2025
