Daily Air Quality Index summaries from EPA monitors in Muscatine, Iowa, 1996–2025.
66%
Good days in 2025
43
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 Muscatine, Iowa on 365 days. 241 of those days (66%) were in the Good range, and the median daily AQI was 43. That median is about the same as 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 365 days. Across the years with fuller monitoring, the share of Good days fell: an average of 74% in 2000–2002 versus 64% in 2023–2025.
Years with fewer than 120 monitored days (1996, 1997, 1998, 1999) 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)
365
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
365
241
122
2
0
0
0
43
59
141
PM2.5
2024
366
269
97
0
0
0
0
38
56
78
PM2.5
2023
365
189
172
1
2
1
0
49
66
207
PM2.5
2022
365
235
130
0
0
0
0
42
58
89
PM2.5
2021
365
211
154
0
0
0
0
45
63
90
PM2.5
2020
366
245
120
1
0
0
0
40
59
124
PM2.5
2019
365
238
127
0
0
0
0
42
61
93
PM2.5
2018
365
154
211
0
0
0
0
52
66
95
PM2.5
2017
365
176
189
0
0
0
0
51
64
80
PM2.5
2016
366
188
178
0
0
0
0
49
63
96
PM2.5
2015
365
183
181
1
0
0
0
50
65
142
PM2.5
2014
365
157
203
5
0
0
0
53
77
135
PM2.5
2013
365
100
260
5
0
0
0
57
74
135
PM2.5
2012
366
124
238
3
1
0
0
55
72
155
PM2.5
2011
365
117
246
2
0
0
0
57
76
142
PM2.5
2010
365
101
248
13
3
0
0
57
85
157
PM2.5
2009
365
141
218
5
1
0
0
55
79
164
PM2.5
2008
334
140
189
5
0
0
0
53
76
138
PM2.5
2007
339
132
198
7
2
0
0
56
82
156
PM2.5
2006
126
54
72
0
0
0
0
53
73
95
PM2.5
2005
304
219
80
5
0
0
0
31
68
121
PM10
2004
366
290
73
2
1
0
0
25
60
154
PM10
2003
359
277
78
4
0
0
0
27
66
122
PM10
2002
365
272
93
0
0
0
0
31
65
97
PM10
2001
365
275
86
4
0
0
0
30
63
143
PM10
2000
304
217
86
1
0
0
0
32
65
101
PM10
1999
119
49
69
1
0
0
0
56
77
120
PM2.5
1998
60
57
3
0
0
0
0
28
43
57
PM10
1997
55
54
1
0
0
0
0
27
47
56
PM10
1996
57
55
2
0
0
0
0
27
41
61
PM10
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
