Daily Air Quality Index summaries from EPA monitors in Scott, Iowa, 1980–2025.
59%
Good days in 2025
46
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 Scott, Iowa on 365 days. 215 of those days (59%) were in the Good range, and the median daily AQI was 46. That median is higher than the typical monitored county in Iowa (median 43.5 across 14 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 155 days. Across the years with fuller monitoring, the share of Good days fell: an average of 88% in 1980–1982 versus 53% 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)
155
42%
Ozone
149
41%
Coarse particles (PM10)
61
17%
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
215
148
1
1
0
0
46
71
159
PM2.5
2024
366
224
142
0
0
0
0
46
61
90
PM2.5
2023
365
142
200
19
3
1
0
53
77
219
PM2.5
2022
365
202
163
0
0
0
0
49
65
96
PM2.5
2021
365
145
219
1
0
0
0
53
70
102
PM2.5
2020
366
173
190
2
1
0
0
52
66
156
PM2.5
2019
365
168
195
2
0
0
0
52
69
112
PM2.5
2018
365
100
261
4
0
0
0
56
72
108
PM2.5
2017
365
88
276
1
0
0
0
56
71
103
PM2.5
2016
366
62
302
2
0
0
0
60
75
112
PM2.5
2015
365
65
298
1
1
0
0
61
77
153
PM2.5
2014
365
45
316
4
0
0
0
59
78
111
PM2.5
2013
365
69
293
3
0
0
0
59
75
126
PM2.5
2012
366
67
291
8
0
0
0
59
80
134
PM2.5
2011
365
66
298
1
0
0
0
59
79
105
PM2.5
2010
365
76
283
6
0
0
0
60
83
117
PM2.5
2009
365
124
238
3
0
0
0
56
77
112
PM2.5
2008
366
110
251
4
1
0
0
57
79
156
PM2.5
2007
365
72
279
13
1
0
0
63
87
152
PM2.5
2006
365
106
255
4
0
0
0
57
77
111
PM2.5
2005
365
87
249
29
0
0
0
61
93
140
PM2.5
2004
366
151
210
5
0
0
0
53
77
136
PM2.5
2003
365
127
220
18
0
0
0
55
87
140
PM2.5
2002
365
121
226
16
2
0
0
57
87
192
PM2.5
2001
365
108
238
19
0
0
0
58
90
147
PM2.5
2000
366
99
256
10
1
0
0
58
81
151
PM2.5
1999
363
174
173
13
3
0
0
51
87
164
PM10
1998
365
254
103
7
1
0
0
41
72
156
PM10
1997
363
196
159
8
0
0
0
48
77
140
PM10
1996
366
212
139
14
1
0
0
46
74
159
PM10
1995
360
269
76
12
3
0
0
37
77
156
Ozone
1994
353
274
71
6
2
0
0
37
74
154
Ozone
1993
336
289
41
6
0
0
0
36
60
143
Ozone
1992
325
269
36
16
4
0
0
35
74
182
Ozone
1991
365
287
60
16
2
0
0
36
77
156
Ozone
1990
349
311
33
4
1
0
0
33
51
164
Ozone
1989
354
270
57
22
5
0
0
38
87
200
Ozone
1988
365
247
54
47
16
1
0
37
126
202
Ozone
1987
362
281
61
17
3
0
0
34
80
179
Ozone
1986
352
293
51
8
0
0
0
35
64
133
Ozone
1985
361
301
52
8
0
0
0
36
71
129
Ozone
1984
348
292
44
12
0
0
0
35
74
140
Ozone
1983
344
262
57
24
1
0
0
34
97
172
Ozone
1982
289
264
23
2
0
0
0
31
49
115
Ozone
1981
208
198
10
0
0
0
0
28
45
97
Ozone
1980
293
226
43
11
12
1
0
33
90
240
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 Iowa with a similar median AQI in 2025
