Muscatine, IA Air Quality

EPA monitor data through 2025 · Updated September 02, 2026 · Methods

In 2025, Muscatine, IA recorded 2 days above an Air Quality Index of 100, the level at which EPA begins warning sensitive groups, out of 365 days with monitoring data. The rest of the year was 241 Good days and 122 Moderate days. Most of the bad days were driven by fine particles. Under the AQI rules that applied before 2013, the same air would have scored 2 days.

Unhealthy days, 2025
2
AQI above 100
Same air, pre-2013 rules
2
for comparison with older reports
Good-air days
241
AQI 50 or below
Days monitored
365
full year

Unhealthy days by year, scored two ways

EPA changed what an AQI of 100 means in 2013 and again in 2015, so a count published before those changes is not comparable to one published after. Each panel below applies a single fixed rulebook to every year, so each is internally consistent. Why this matters.

Scored by today's rules

Muscatine, IA: days above AQI 100 by year, current rules 0 4 8 12 16 2000 2005 2010 2015 2020 2025 2000: 1 days 2001: 4 days 2002: 0 days 2003: 4 days 2004: 3 days 2005: 5 days 2006: 0 days 2007: 9 days 2008: 5 days 2009: 6 days 2010: 16 days 2011: 2 days 2012: 4 days 2013: 5 days 2014: 5 days 2015: 1 days 2016: 0 days 2017: 0 days 2018: 0 days 2019: 0 days 2020: 1 days 2021: 0 days 2022: 0 days 2023: 4 days 2024: 0 days 2025: 2 days

Scored by the pre-2013 rules

Muscatine, IA: days above AQI 100 by year, pre-2013 rules 0 4 8 12 16 2000 2005 2010 2015 2020 2025 2000: 0 days 2001: 2 days 2002: 0 days 2003: 1 days 2004: 1 days 2005: 1 days 2006: 0 days 2007: 9 days 2008: 3 days 2009: 3 days 2010: 8 days 2011: 2 days 2012: 2 days 2013: 3 days 2014: 2 days 2015: 1 days 2016: 0 days 2017: 0 days 2018: 0 days 2019: 0 days 2020: 1 days 2021: 0 days 2022: 0 days 2023: 4 days 2024: 0 days 2025: 2 days

What 2025 looked like

Air quality categoryDaysShare of days with an AQI
Good24166%
Moderate12233%
Unhealthy for sensitive groups21%
Unhealthy or worse00%

Median AQI 43 · 90th-percentile AQI 59 · worst day 141. Scored under current rules, out of 365 days with an AQI.

What drove the unhealthy days

Of the 2 days above 100 in 2025, 0 were driven by ozone and 2 by fine particles. The two behave differently. Ozone peaks on hot sunny afternoons; fine particles now spike mainly with wildfire smoke.

The unhealthy days in 2025

Every day the index passed 100, what it reached, and which pollutant drove it.

DatePeak AQIDriven byPre-2013 score
Jul 31141Fine particles 123
Aug 1114Fine particles 102

Statewide context

Muscatine, IA sits in Iowa.

Days in each air quality category, by year

How many days fell in each AQI category, for every year with an AQI on record. Categories are scored under EPA's current breakpoints. A year with fewer than 300 days is marked, because a short year lowers every count for reasons that have nothing to do with the air.

YearGoodModerate Unhealthy for sensitive groupsUnhealthy or worse Days with an AQI
2000 217861 0304
2001 275864 0365
2002 272930 0365
2003 277784 0359
2004 290732 1366
2005 219805 0304
2006 (partial) 54720 0126
2007 1321987 2339
2008 1401895 0334
2009 1412185 1365
2010 10124813 3365
2011 1172462 0365
2012 1242383 1366
2013 1002605 0365
2014 1572035 0365
2015 1831811 0365
2016 1881780 0366
2017 1761890 0365
2018 1542110 0365
2019 2381270 0365
2020 2451201 0366
2021 2111540 0365
2022 2351300 0365
2023 1891721 3365
2024 269970 0366
2025 2411222 0365

Good is AQI 0–50, Moderate 51–100, Unhealthy for sensitive groups 101–150. “Unhealthy or worse” combines the Unhealthy, Very Unhealthy and Hazardous categories, which are shown together because most areas record too few of each to report separately. The four columns sum to the last one by construction. These counts exclude sulphur dioxide, following EPA, which drops SO₂ from county and metro summaries because it is too localized to describe a whole area.

The full series

The same years scored two ways, with the pollutant that drove the days above 100. EPA's files record which pollutant set each day's AQI; they do not attribute days to wildfire smoke, so no column here claims to.

YearUnhealthy days, current rulesOf which ozone Of which fine particlesPre-2013 rulesDays monitored
20001 0 1 0366
20014 0 4 2365
20020 0 0 0365
20034 0 4 1365
20043 0 3 1366
20055 0 5 1365
20060 0 0 0365
20079 0 9 9365
20085 0 5 3361
20096 0 6 3365
201016 0 16 8365
20112 0 2 2365
20124 0 4 2366
20135 0 5 3365
20145 0 5 2365
20151 0 1 1365
20160 0 0 0366
20170 0 0 0365
20180 0 0 0365
20190 0 0 0365
20201 0 1 1366
20210 0 0 0365
20220 0 0 0365
20234 0 4 4365
20240 0 0 0366
20252 0 2 2365

Sources