Daily Air Quality Index summaries from EPA monitors in Jefferson, Alabama, 1980–2025.
44%
Good days in 2025
52
Median daily AQI, 2025
2
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 Jefferson, Alabama on 365 days. 159 of those days (44%) were in the Good range, and the median daily AQI was 52. That median is higher than the typical monitored county in Alabama (median 41 across 14 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 285 days. Across the years with fuller monitoring, the share of Good days fell: an average of 47% in 1980–1982 versus 30% 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)
285
78%
Ozone
78
21%
Nitrogen dioxide (NO₂)
2
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
159
204
2
0
0
0
52
68
117
PM2.5
2024
366
95
265
6
0
0
0
57
79
119
PM2.5
2023
365
73
272
15
3
2
0
61
89
255
PM2.5
2022
365
128
235
2
0
0
0
54
71
105
PM2.5
2021
365
104
256
3
2
0
0
56
77
189
PM2.5
2020
366
119
244
3
0
0
0
54
70
129
PM2.5
2019
365
85
267
13
0
0
0
58
80
150
PM2.5
2018
365
98
263
3
1
0
0
56
76
156
PM2.5
2017
365
104
258
3
0
0
0
56
73
129
PM2.5
2016
366
105
252
8
1
0
0
56
77
151
PM2.5
2015
365
106
254
5
0
0
0
55
73
147
PM2.5
2014
365
69
290
6
0
0
0
58
75
112
PM2.5
2013
365
95
268
2
0
0
0
56
71
129
PM2.5
2012
366
70
276
16
4
0
0
58
85
172
PM2.5
2011
365
64
263
32
6
0
0
61
101
182
PM2.5
2010
365
55
280
26
4
0
0
63
97
166
PM2.5
2009
365
66
293
6
0
0
0
60
79
150
PM2.5
2008
366
19
318
25
4
0
0
70
97
174
PM2.5
2007
365
12
280
56
16
1
0
76
127
203
PM2.5
2006
365
10
286
56
12
1
0
80
118
204
PM2.5
2005
365
8
297
51
9
0
0
77
116
177
PM2.5
2004
366
19
307
36
4
0
0
71
101
166
PM2.5
2003
365
12
308
43
2
0
0
72
105
177
PM2.5
2002
365
14
291
49
10
1
0
71
115
207
PM2.5
2001
365
13
251
71
22
8
0
80
144
265
PM2.5
2000
366
8
256
73
25
4
0
81
140
208
PM2.5
1999
365
7
250
69
33
6
0
83
152
273
PM2.5
1998
365
214
96
34
16
5
0
46
122
212
Ozone
1997
365
221
107
29
7
1
0
44
101
202
Ozone
1996
366
246
86
19
11
4
0
43
97
217
Ozone
1995
365
219
87
31
23
5
0
46
140
222
Ozone
1994
365
254
93
15
3
0
0
43
83
166
Ozone
1993
365
225
113
21
5
1
0
45
93
205
Ozone
1992
366
228
112
19
7
0
0
43
90
195
Ozone
1991
365
233
109
18
5
0
0
43
90
166
Ozone
1990
365
187
114
37
25
2
0
50
133
203
Ozone
1989
365
210
129
22
4
0
0
46
93
177
Ozone
1988
366
183
124
34
19
6
0
51
129
223
Ozone
1987
365
167
158
36
4
0
0
52
105
182
Ozone
1986
365
185
135
38
6
1
0
50
108
224
Ozone
1985
365
202
130
25
7
1
0
48
100
202
Ozone
1984
366
219
125
19
3
0
0
45
89
174
Ozone
1983
365
184
121
43
10
7
0
50
122
243
Ozone
1982
365
185
109
50
17
4
0
50
129
228
Ozone
1981
365
145
127
53
31
9
0
64
156
239
Ozone
1980
348
176
109
37
19
7
0
50
140
221
CO
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 Alabama with a similar median AQI in 2025
