Daily Air Quality Index summaries from EPA monitors in Roane, Tennessee, 1981–2025.
89%
Good days in 2025
29
Median daily AQI, 2025
0
Days above 100 in 2025
360
Days with an AQI in 2025 (of 365)
In 2025, EPA reported a daily Air Quality Index (AQI) for Roane, Tennessee on 360 days. 319 of those days (89%) were in the Good range, and the median daily AQI was 29. That median is lower than the typical monitored county in Tennessee (median 39 across 23 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 360 days. Across the years with fuller monitoring, the share of Good days rose: an average of 74% in 1981–1983 versus 80% in 2023–2025.
Years with fewer than 120 monitored days (2003, 2004, 2005, 2006, 2008, 2016…) 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)
360
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
360
319
41
0
0
0
0
29
52
68
PM2.5
2024
361
285
76
0
0
0
0
35
54
72
PM2.5
2023
357
258
97
2
0
0
0
36
57
106
PM2.5
2022
340
273
66
0
1
0
0
36
55
162
PM2.5
2021
357
256
101
0
0
0
0
37
57
89
PM2.5
2020
338
272
66
0
0
0
0
35
55
92
PM2.5
2019
356
251
105
0
0
0
0
37
55
75
PM2.5
2018
355
267
88
0
0
0
0
36
56
66
PM2.5
2017
303
204
99
0
0
0
0
41
57
73
PM2.5
2016
117
70
46
0
1
0
0
42
58
166
PM2.5
2015
120
64
56
0
0
0
0
49
62
73
PM2.5
2014
281
92
189
0
0
0
0
53
63
85
PM2.5
2013
365
69
295
1
0
0
0
58
71
121
PM2.5
2012
366
54
312
0
0
0
0
59
70
90
PM2.5
2011
365
46
318
0
1
0
0
61
75
168
PM2.5
2010
354
107
247
0
0
0
0
57
73
96
PM2.5
2009
354
274
79
0
1
0
0
20
61
152
PM10
2008
62
62
0
0
0
0
0
25
42
50
PM10
2007
121
26
95
0
0
0
0
58
81
98
PM2.5
2006
117
34
83
0
0
0
0
57
76
96
PM2.5
2005
118
27
91
0
0
0
0
59
82
98
PM2.5
2004
115
29
86
0
0
0
0
57
78
92
PM2.5
2003
115
38
77
0
0
0
0
57
77
92
PM2.5
2002
120
41
79
0
0
0
0
57
75
88
PM2.5
2001
121
32
86
2
1
0
0
59
84
155
PM2.5
2000
323
147
142
28
5
1
0
52
105
203
Ozone
1999
246
114
85
35
12
0
0
54
126
192
Ozone
1998
66
64
2
0
0
0
0
29
42
59
PM10
1997
64
58
6
0
0
0
0
24
50
61
PM10
1996
66
64
2
0
0
0
0
23
43
54
PM10
1995
64
61
3
0
0
0
0
27
44
57
PM10
1994
103
99
4
0
0
0
0
23
44
64
PM10
1993
91
84
7
0
0
0
0
29
49
89
PM10
1992
38
37
1
0
0
0
0
26
40
51
PM10
1984
239
163
51
23
2
0
0
42
101
172
Ozone
1983
357
243
56
47
11
0
0
39
115
185
Ozone
1982
356
278
60
17
1
0
0
36
77
161
Ozone
1981
352
272
65
15
0
0
0
35
84
136
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 Tennessee with a similar median AQI in 2025
