Daily Air Quality Index summaries from EPA monitors in Perry, Kentucky, 1988–2025.
87%
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 Perry, Kentucky on 365 days. 318 of those days (87%) were in the Good range, and the median daily AQI was 36. That median is lower than the typical monitored county in Kentucky (median 39 across 25 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 204 days. Across the years with fuller monitoring, the share of Good days held roughly steady: an average of 78% in 1992–1994 versus 77% in 2023–2025.
Years with fewer than 120 monitored days (1988, 1989, 1990, 1991) 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)
204
56%
Ozone
161
44%
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
318
46
0
1
0
0
36
52
172
PM2.5
2024
352
290
61
1
0
0
0
40
55
117
PM2.5
2023
365
223
138
4
0
0
0
45
65
137
PM2.5
2022
348
226
119
1
2
0
0
46
59
171
PM2.5
2021
365
247
118
0
0
0
0
44
60
93
PM2.5
2020
364
278
86
0
0
0
0
39
55
99
PM2.5
2019
353
238
115
0
0
0
0
44
57
87
PM2.5
2018
364
205
159
0
0
0
0
48
61
80
PM2.5
2017
352
209
143
0
0
0
0
47
59
84
PM2.5
2016
352
165
185
1
1
0
0
51
61
168
PM2.5
2015
361
256
105
0
0
0
0
43
57
84
PM2.5
2014
350
202
148
0
0
0
0
47
61
84
PM2.5
2013
361
253
108
0
0
0
0
42
58
77
PM2.5
2012
361
128
230
3
0
0
0
54
66
126
PM2.5
2011
361
234
127
0
0
0
0
44
61
87
PM2.5
2010
357
214
139
4
0
0
0
46
65
115
PM2.5
2009
357
255
102
0
0
0
0
41
58
85
PM2.5
2008
256
173
77
6
0
0
0
46
75
115
Ozone
2007
265
124
126
14
1
0
0
53
93
161
Ozone
2006
267
156
106
5
0
0
0
47
80
115
Ozone
2005
265
143
112
10
0
0
0
48
84
133
Ozone
2004
264
173
90
1
0
0
0
44
67
101
Ozone
2003
265
176
84
5
0
0
0
44
71
147
Ozone
2002
252
147
88
15
2
0
0
47
90
156
Ozone
2001
265
165
90
8
0
2
0
44
77
251
Ozone
2000
263
187
67
8
1
0
0
41
77
168
Ozone
1999
231
170
53
7
1
0
0
44
74
154
Ozone
1998
240
206
28
6
0
0
0
36
67
133
Ozone
1997
239
208
31
0
0
0
0
36
54
80
Ozone
1996
237
211
24
2
0
0
0
34
54
143
Ozone
1995
238
181
46
10
1
0
0
41
80
159
Ozone
1994
231
178
47
5
1
0
0
40
77
154
Ozone
1993
237
181
52
4
0
0
0
42
74
129
Ozone
1992
240
195
40
4
1
0
0
38
64
156
Ozone
1991
60
56
4
0
0
0
0
31
49
64
PM10
1990
57
50
7
0
0
0
0
29
51
78
PM10
1989
60
47
13
0
0
0
0
39
56
64
PM10
1988
20
17
3
0
0
0
0
29
61
64
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 Kentucky with a similar median AQI in 2025
