Daily Air Quality Index summaries from EPA monitors in Woodbury, Iowa, 1980–2025.
80%
Good days in 2025
39
Median daily AQI, 2025
3
Days above 100 in 2025
284
Days with an AQI in 2025 (of 365)
In 2025, EPA reported a daily Air Quality Index (AQI) for Woodbury, Iowa on 284 days. 226 of those days (80%) were in the Good range, and the median daily AQI was 39. That median is lower than the typical monitored county in Iowa (median 43.5 across 14 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 207 days. Across the years with fuller monitoring, the share of Good days held roughly steady: an average of 80% in 1980–1999 versus 78% in 2020–2025.
EPA did not report an AQI for every day of 2025 here (284 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.
Years with fewer than 120 monitored days (1997, 1998, 2019, 2021, 2022, 2023…) 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
Ozone
207
73%
Fine particles (PM2.5)
77
27%
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
284
226
55
3
0
0
0
39
61
122
Ozone
2024
284
224
60
0
0
0
0
43
58
93
Ozone
2023
118
71
45
0
2
0
0
43
64
169
PM2.5
2022
113
91
22
0
0
0
0
36
56
76
PM2.5
2021
115
79
35
0
1
0
0
42
63
168
PM2.5
2020
122
92
30
0
0
0
0
39
56
81
PM2.5
2019
118
91
27
0
0
0
0
38
58
83
PM2.5
2018
122
81
41
0
0
0
0
44
58
93
PM2.5
2017
122
87
35
0
0
0
0
37
56
72
PM2.5
2016
127
96
31
0
0
0
0
36
58
66
PM2.5
2015
121
90
31
0
0
0
0
38
56
99
PM2.5
2014
123
84
37
2
0
0
0
39
59
108
PM2.5
2013
122
79
42
1
0
0
0
42
66
121
PM2.5
2012
123
69
54
0
0
0
0
47
66
92
PM2.5
2011
125
80
45
0
0
0
0
43
65
80
PM2.5
2010
123
69
53
1
0
0
0
45
70
127
PM2.5
2009
123
78
44
1
0
0
0
42
66
113
PM2.5
2008
125
66
58
1
0
0
0
47
66
106
PM2.5
2007
125
64
59
2
0
0
0
49
68
126
PM2.5
2006
122
61
61
0
0
0
0
51
70
90
PM2.5
2005
124
65
58
1
0
0
0
49
71
130
PM2.5
2004
124
65
59
0
0
0
0
47
66
97
PM2.5
2003
121
59
62
0
0
0
0
51
69
92
PM2.5
2002
124
77
47
0
0
0
0
43
69
88
PM2.5
2001
124
65
58
1
0
0
0
49
68
101
PM2.5
2000
122
73
49
0
0
0
0
42
69
96
PM2.5
1999
121
73
48
0
0
0
0
43
68
85
PM2.5
1998
56
53
3
0
0
0
0
25
42
55
PM10
1997
53
49
4
0
0
0
0
22
49
74
PM10
1996
52
43
9
0
0
0
0
24
59
77
PM10
1995
55
49
6
0
0
0
0
19
51
59
PM10
1994
60
58
2
0
0
0
0
19
39
59
PM10
1993
59
58
1
0
0
0
0
18
37
52
PM10
1992
42
40
2
0
0
0
0
19
41
70
PM10
1991
58
56
2
0
0
0
0
23
46
58
PM10
1990
58
56
2
0
0
0
0
22
43
60
PM10
1989
61
57
4
0
0
0
0
22
43
64
PM10
1988
58
54
4
0
0
0
0
27
48
72
PM10
1987
22
22
0
0
0
0
0
22
36
48
PM10
1981
121
120
1
0
0
0
0
17
30
70
NO2
1980
245
196
38
10
1
0
0
35
74
151
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
