Daily Air Quality Index summaries from EPA monitors in Beaver, Pennsylvania, 1980–2025.
56%
Good days in 2025
46
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 Beaver, Pennsylvania on 365 days. 203 of those days (56%) were in the Good range, and the median daily AQI was 46. That median is higher than the typical monitored county in Pennsylvania (median 40 across 38 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 186 days. Across the years with fuller monitoring, the share of Good days fell: an average of 71% in 1980–1982 versus 52% in 2023–2025.
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)
186
51%
Ozone
178
49%
Nitrogen dioxide (NO₂)
1
<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
203
161
1
0
0
0
46
71
131
PM2.5
2024
366
212
153
1
0
0
0
46
68
112
Ozone
2023
365
158
197
8
0
2
0
52
78
235
PM2.5
2022
364
174
189
1
0
0
0
51
66
112
PM2.5
2021
365
170
192
3
0
0
0
52
67
125
PM2.5
2020
366
205
160
1
0
0
0
48
64
142
PM2.5
2019
365
183
181
1
0
0
0
50
67
132
PM2.5
2018
365
169
190
6
0
0
0
52
73
136
PM2.5
2017
365
139
224
2
0
0
0
54
71
105
PM2.5
2016
366
170
192
4
0
0
0
52
69
126
PM2.5
2015
365
174
186
5
0
0
0
51
73
122
PM2.5
2014
365
150
210
5
0
0
0
53
72
119
PM2.5
2013
365
150
209
5
1
0
0
53
72
166
PM2.5
2012
366
103
246
15
2
0
0
58
80
161
PM2.5
2011
365
135
221
9
0
0
0
55
75
140
PM2.5
2010
365
144
211
9
1
0
0
54
83
151
PM2.5
2009
365
131
234
0
0
0
0
57
78
100
PM2.5
2008
366
240
117
9
0
0
0
43
77
129
Ozone
2007
365
207
136
20
2
0
0
46
87
169
Ozone
2006
365
213
132
19
1
0
0
45
87
156
Ozone
2005
365
201
128
31
5
0
0
47
100
195
Ozone
2004
366
227
123
16
0
0
0
43
80
147
Ozone
2003
365
201
140
19
3
2
0
47
90
217
Ozone
2002
365
207
114
20
21
3
0
47
119
202
Ozone
2001
365
197
122
33
13
0
0
48
108
190
Ozone
2000
366
224
120
19
3
0
0
44
83
187
Ozone
1999
365
251
71
32
9
2
0
42
105
216
Ozone
1998
365
240
79
31
14
1
0
40
108
205
Ozone
1997
365
272
66
21
6
0
0
39
90
190
Ozone
1996
366
263
67
28
8
0
0
40
100
169
Ozone
1995
365
268
69
22
6
0
0
39
93
174
NO2
1994
361
280
59
17
5
0
0
40
87
177
NO2
1993
365
253
82
22
8
0
0
41
93
195
Ozone
1992
364
294
51
15
4
0
0
38
71
166
Ozone
1991
365
237
77
35
16
0
0
41
119
195
Ozone
1990
364
282
61
19
2
0
0
39
80
156
Ozone
1989
365
262
76
21
6
0
0
41
93
174
Ozone
1988
366
256
57
17
28
7
1
42
147
388
Ozone
1987
365
248
79
27
10
1
0
42
101
226
Ozone
1986
364
283
61
18
2
0
0
38
80
187
Ozone
1985
364
239
95
24
4
2
0
43
97
210
Ozone
1984
366
248
89
24
5
0
0
44
93
169
NO2
1983
364
246
77
25
14
2
0
41
108
209
Ozone
1982
364
279
65
18
2
0
0
39
77
166
Ozone
1981
364
273
63
19
8
1
0
38
84
203
Ozone
1980
363
227
99
27
8
2
0
45
101
225
NO2
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 Pennsylvania with a similar median AQI in 2025
