Cedar Rapids, IA Air Quality

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

In 2025, Cedar Rapids, IA recorded 5 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 224 Good days and 136 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 3 days. Since 2000, unhealthy days are 0% higher on a consistent definition.

Unhealthy days, 2025
5
AQI above 100
Same air, pre-2013 rules
3
for comparison with older reports
Good-air days
224
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

Cedar Rapids, IA: days above AQI 100 by year, current rules 0 4 8 12 16 20 2000 2005 2010 2015 2020 2025 2000: 8 days 2001: 7 days 2002: 11 days 2003: 9 days 2004: 2 days 2005: 13 days 2006: 1 days 2007: 7 days 2008: 2 days 2009: 4 days 2010: 6 days 2011: 0 days 2012: 4 days 2013: 1 days 2014: 1 days 2015: 1 days 2016: 1 days 2017: 0 days 2018: 4 days 2019: 0 days 2020: 1 days 2021: 4 days 2022: 0 days 2023: 18 days 2024: 0 days 2025: 5 days

Scored by the pre-2013 rules

Cedar Rapids, IA: days above AQI 100 by year, pre-2013 rules 0 4 8 12 16 20 2000 2005 2010 2015 2020 2025 2000: 3 days 2001: 5 days 2002: 2 days 2003: 3 days 2004: 0 days 2005: 4 days 2006: 0 days 2007: 6 days 2008: 1 days 2009: 0 days 2010: 0 days 2011: 0 days 2012: 1 days 2013: 1 days 2014: 0 days 2015: 0 days 2016: 0 days 2017: 0 days 2018: 1 days 2019: 0 days 2020: 0 days 2021: 1 days 2022: 0 days 2023: 12 days 2024: 0 days 2025: 3 days

What 2025 looked like

Air quality categoryDaysShare of days with an AQI
Good22462%
Moderate13637%
Unhealthy for sensitive groups41%
Unhealthy or worse10%

Median AQI 44 · 90th-percentile AQI 68 · worst day 163. Scored under current rules, out of 365 days with an AQI.

What drove the unhealthy days

Of the 5 days above 100 in 2025, 1 were driven by ozone and 4 by fine particles. The two behave differently. Ozone peaks on hot sunny afternoons; fine particles now spike mainly with wildfire smoke. In the eastern United States, ozone has stopped responding to emission cuts: nitrogen oxide emissions kept falling after 2014 and ambient ozone barely moved.

The unhealthy days in 2025

Every day the index passed 100, what it reached, and which pollutant drove it. 2 of these 5 would not have counted as unhealthy under the pre-2013 rules.

DatePeak AQIDriven byPre-2013 score
May 12101Ozone 87 (not unhealthy)
Jun 4123Fine particles 108
Jul 31163Fine particles 155
Aug 1122Fine particles 108
Aug 2108Fine particles 96 (not unhealthy)

Statewide context

Cedar Rapids, 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 1761827 1366
2001 1691897 0365
2002 17917511 0365
2003 1801769 0365
2004 1941702 0366
2005 17018213 0365
2006 274901 0365
2007 264947 0365
2008 1472172 0366
2009 1661954 0365
2010 1452146 0365
2011 1711940 0365
2012 1592034 0366
2013 1701941 0365
2014 1871771 0365
2015 1951691 0365
2016 1971681 0366
2017 2221430 0365
2018 1851764 0365
2019 2231420 0365
2020 2071581 0366
2021 1602014 0365
2022 1981670 0365
2023 13021714 4365
2024 2351310 0366
2025 2241364 1365

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
20008 6 2 3366
20017 3 4 5365
200211 9 2 2365
20039 1 8 3365
20042 0 2 0366
200513 5 8 4365
20061 0 1 0365
20077 6 1 6365
20082 0 2 1366
20094 0 4 0365
20106 1 5 0365
20110 0 0 0365
20124 4 0 1366
20131 0 1 1365
20141 0 1 0365
20151 0 1 0365
20161 0 1 0366
20170 0 0 0365
20184 4 0 1365
20190 0 0 0365
20201 1 0 0366
20214 0 4 1365
20220 0 0 0365
202318 12 6 12365
20240 0 0 0366
20255 1 4 3365

Sources