Daily Air Quality Index summaries from EPA monitors in Christian, Kentucky, 1993–2025.
73%
Good days in 2025
41
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 Christian, Kentucky on 364 days. 266 of those days (73%) were in the Good range, and the median daily AQI was 41. That median is about the same as the typical monitored county in Kentucky (median 39 across 25 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 228 days. Across the years with fuller monitoring, the share of Good days rose: an average of 65% in 1993–1996 versus 69% in 2023–2025.
Years with fewer than 120 monitored days (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)
228
63%
Ozone
136
37%
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
266
98
0
0
0
0
41
57
87
PM2.5
2024
360
274
86
0
0
0
0
42
56
84
PM2.5
2023
365
213
147
5
0
0
0
47
63
117
PM2.5
2022
365
201
164
0
0
0
0
48
65
85
PM2.5
2021
365
190
175
0
0
0
0
49
67
99
PM2.5
2020
320
249
71
0
0
0
0
41
56
85
Ozone
2019
278
228
50
0
0
0
0
40
54
80
Ozone
2018
280
217
63
0
0
0
0
41
58
90
Ozone
2017
280
230
50
0
0
0
0
41
56
71
Ozone
2016
283
223
60
0
0
0
0
41
58
90
Ozone
2015
270
196
74
0
0
0
0
44
61
87
Ozone
2014
277
195
82
0
0
0
0
43
62
90
Ozone
2013
279
189
89
1
0
0
0
44
61
101
Ozone
2012
284
162
110
12
0
0
0
48
84
122
Ozone
2011
279
150
127
2
0
0
0
49
74
108
Ozone
2010
281
133
140
8
0
0
0
51
80
122
Ozone
2009
268
183
84
1
0
0
0
44
64
136
Ozone
2008
285
150
131
4
0
0
0
49
80
115
Ozone
2007
284
106
135
37
6
0
0
58
112
166
Ozone
2006
282
135
134
13
0
0
0
51
84
136
Ozone
2005
286
132
133
21
0
0
0
53
90
150
Ozone
2004
278
146
125
7
0
0
0
50
80
129
Ozone
2003
283
126
128
28
1
0
0
54
101
151
Ozone
2002
279
134
114
25
6
0
0
51
105
179
Ozone
2001
279
123
130
25
1
0
0
54
100
159
Ozone
2000
257
98
130
28
1
0
0
58
101
159
Ozone
1999
264
85
126
41
10
2
0
61
129
204
Ozone
1998
214
91
88
29
6
0
0
58
112
195
Ozone
1997
216
118
80
18
0
0
0
48
100
150
Ozone
1996
300
211
74
15
0
0
0
44
87
147
Ozone
1995
91
52
32
7
0
0
0
47
90
150
Ozone
1994
199
95
73
26
5
0
0
54
112
185
Ozone
1993
348
267
63
18
0
0
0
41
80
147
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
