Kokomo, IN Air Quality

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

In 2025, Kokomo, IN recorded 3 days above an Air Quality Index of 100, the level at which EPA begins warning sensitive groups, out of 362 days with monitoring data. The rest of the year was 241 Good days and 118 Moderate days. Most of the bad days were driven by ozone. Under the AQI rules that applied before 2013, the same air would have scored 1 days.

Unhealthy days, 2025
3
AQI above 100
Same air, pre-2013 rules
1
for comparison with older reports
Good-air days
241
AQI 50 or below
Days monitored
362
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

Kokomo, IN: days above AQI 100 by year, current rules 0 2 4 6 8 10 2000 2005 2010 2015 2020 2025 2000: 1 days (incomplete monitoring) 2001: 3 days (incomplete monitoring) 2002: 2 days (incomplete monitoring) 2003: 2 days (incomplete monitoring) 2004: 0 days (incomplete monitoring) 2005: 3 days (incomplete monitoring) 2006: 0 days (incomplete monitoring) 2007: 1 days (incomplete monitoring) 2008: 0 days (incomplete monitoring) 2009: 0 days (incomplete monitoring) 2010: 1 days (incomplete monitoring) 2011: 0 days (incomplete monitoring) 2012: 0 days (incomplete monitoring) 2014: 0 days (incomplete monitoring) 2015: 1 days 2016: 0 days 2017: 0 days 2018: 5 days 2019: 1 days 2020: 1 days 2021: 2 days 2022: 4 days 2023: 10 days 2024: 0 days 2025: 3 days

Scored by the pre-2013 rules

Kokomo, IN: days above AQI 100 by year, pre-2013 rules 0 2 4 6 8 10 2000 2005 2010 2015 2020 2025 2000: 0 days (incomplete monitoring) 2001: 0 days (incomplete monitoring) 2002: 0 days (incomplete monitoring) 2003: 1 days (incomplete monitoring) 2004: 0 days (incomplete monitoring) 2005: 2 days (incomplete monitoring) 2006: 0 days (incomplete monitoring) 2007: 0 days (incomplete monitoring) 2008: 0 days (incomplete monitoring) 2009: 0 days (incomplete monitoring) 2010: 0 days (incomplete monitoring) 2011: 0 days (incomplete monitoring) 2012: 0 days (incomplete monitoring) 2014: 0 days (incomplete monitoring) 2015: 0 days 2016: 0 days 2017: 0 days 2018: 0 days 2019: 0 days 2020: 0 days 2021: 0 days 2022: 0 days 2023: 7 days 2024: 0 days 2025: 1 days
Faded columns mark years with fewer than 300 monitored days, where the count is not comparable.

What 2025 looked like

Air quality categoryDaysShare of days with an AQI
Good24166%
Moderate11833%
Unhealthy for sensitive groups31%
Unhealthy or worse00%

Median AQI 43 · 90th-percentile AQI 61 · worst day 122. Scored under current rules, out of 362 days with an AQI.

What drove the unhealthy days

Of the 3 days above 100 in 2025, 3 were driven by ozone and 0 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 3 would not have counted as unhealthy under the pre-2013 rules.

DatePeak AQIDriven byPre-2013 score
Jun 12122Ozone 104
Sep 18105Ozone 90 (not unhealthy)
Sep 19112Ozone 97 (not unhealthy)

Statewide context

Kokomo, IN sits in Indiana.

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 (partial) 23881 0112
2001 (partial) 35703 0108
2002 (partial) 29882 0119
2003 (partial) 39752 0116
2004 (partial) 35790 0114
2005 (partial) 29793 0111
2006 (partial) 41730 0114
2007 (partial) 35731 0109
2008 (partial) 42600 0102
2009 (partial) 47630 0110
2010 (partial) 44671 0112
2011 (partial) 47630 0110
2012 (partial) 650 011
2014 (partial) 1011600 0261
2015 1012441 0346
2016 1731520 0325
2017 2111450 0356
2018 2341265 0365
2019 2371241 0362
2020 266991 0366
2021 2301322 0364
2022 2471144 0365
2023 2351208 2365
2024 2411250 0366
2025 2411183 0362

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 0112
20013 0 3 0108
20022 0 2 0119
20032 0 2 1116
20040 0 0 0114
20053 0 3 2111
20060 0 0 0114
20071 0 1 0109
20080 0 0 0102
20090 0 0 0110
20101 0 1 0112
20110 0 0 0110
20120 0 0 011
20140 0 0 0261
20151 0 1 0346
20160 0 0 0325
20170 0 0 0356
20185 5 0 0365
20191 1 0 0362
20201 1 0 0366
20212 2 0 0364
20224 4 0 0365
202310 5 5 7365
20240 0 0 0366
20253 3 0 1362

Sources