Daily Air Quality Index summaries from EPA monitors in Carter, Kentucky, 1983–2025.
89%
Good days in 2025
36
Median daily AQI, 2025
0
Days above 100 in 2025
364
Days with an AQI in 2025 (of 365)
In 2025, EPA reported a daily Air Quality Index (AQI) for Carter, Kentucky on 364 days. 324 of those days (89%) 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 192 days. Across the years with fuller monitoring, the share of Good days rose: an average of 68% in 1983–1987 versus 85% in 2023–2025.
Years with fewer than 120 monitored days (1985, 1991, 1992, 1993, 1994, 1995) 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)
192
53%
Ozone
172
47%
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
364
324
40
0
0
0
0
36
51
82
PM2.5
2024
360
321
39
0
0
0
0
37
51
62
PM2.5
2023
364
284
78
1
1
0
0
40
58
153
PM2.5
2022
361
293
68
0
0
0
0
39
53
71
PM2.5
2021
279
252
27
0
0
0
0
35
50
86
Ozone
2020
285
273
12
0
0
0
0
33
45
64
Ozone
2019
285
266
19
0
0
0
0
37
49
67
Ozone
2018
281
248
33
0
0
0
0
35
52
80
Ozone
2017
285
261
24
0
0
0
0
38
49
77
Ozone
2016
286
253
32
1
0
0
0
38
52
103
Ozone
2015
265
227
38
0
0
0
0
38
54
74
Ozone
2014
283
226
57
0
0
0
0
39
58
90
Ozone
2013
284
227
57
0
0
0
0
41
55
97
Ozone
2012
285
208
72
5
0
0
0
43
59
150
Ozone
2011
277
204
72
0
1
0
0
43
63
157
Ozone
2010
283
172
105
6
0
0
0
47
68
115
Ozone
2009
284
207
77
0
0
0
0
41
58
93
Ozone
2008
278
161
112
5
0
0
0
48
76
140
Ozone
2007
275
158
112
5
0
0
0
47
79
112
Ozone
2006
285
191
91
3
0
0
0
43
71
120
Ozone
2005
278
150
110
17
1
0
0
49
90
154
Ozone
2004
283
199
84
0
0
0
0
43
64
87
Ozone
2003
283
169
106
7
1
0
0
47
78
169
Ozone
2002
281
140
111
26
4
0
0
51
105
172
Ozone
2001
282
143
124
15
0
0
0
50
87
130
Ozone
2000
274
132
130
11
1
0
0
51
87
153
Ozone
1999
241
85
105
39
12
0
0
60
129
190
Ozone
1998
171
69
61
30
11
0
0
64
136
197
Ozone
1995
47
43
4
0
0
0
0
27
49
57
PM10
1994
56
50
6
0
0
0
0
24
51
62
PM10
1993
58
56
2
0
0
0
0
22
44
52
PM10
1992
56
56
0
0
0
0
0
23
35
45
PM10
1991
45
45
0
0
0
0
0
29
44
49
PM10
1987
179
128
51
0
0
0
0
40
61
86
PM10
1986
232
181
51
0
0
0
0
36
55
83
PM10
1985
14
11
3
0
0
0
0
36
61
68
PM10
1983
184
100
61
17
6
0
0
49
108
177
Ozone
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
